Mitsubishi EHST20C-VM2C Service Manual
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Mitsubishi EHST20C-VM2C Service Manual

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SERVICE MANUAL
[Model Name]
EHST20C-VM2C
EHST20C-VM6C
EHST20C-YM9C
EHST20C-TM9C
EHST20C-VM2EC
EHST20C-VM6EC
EHST20C-YM9EC
EHST20C-MHCW
EHST20C-MEC
EHST20D-VM2C
EHST20D-VM2EC
EHST20D-YM9C
EHST20D-MHCW
EHST20D-MEC
EHST20D-MHC
[Service Ref.]
Refer To page 2.
EHPT20X-VM2C
EHPT20X-VM6C
EHPT20X-YM9C
EHPT20X-TM9C
EHPT20X-MHCW
ERST20C-VM2C
ERST20C-MEC
ERST20D-VM2C
ERST20D-MEC
Notes:
• This manual describes service
data of cylinder unit only.
• RoHS compliant products have
<G> mark on the spec name plate.
MAIN REMOTE
CONTROLLER
R410A
Revision:
• Added EHST20C-VM2CR2.UK,
EHST20C-VM6CR2.UK,
EHST20C-YM9CR2.UK,
EHST20C-TM9CR2.UK,
EHST20C-VM2ECR2.UK,
EHST20C-VM6ECR2.UK,
EHST20C-YM9ECR2.UK,
EHST20C-MHCWR2.UK,
EHST20C-MECR2.UK,
EHST20D-VM2CR2.UK,
EHST20D-VM2ECR2.UK,
EHST20D-YM9CR2.UK,
EHST20D-MHCWR2.UK,
EHST20D-MECR2.UK,
EHST20D-MHCR2.UK,
EHPT20X-VM2CR2.UK,
EHPT20X-VM6CR2.UK,
EHPT20X-YM9CR2.UK,
EHPT20X-TM9CR2.UK,
EHPT20X-MHCWR2.UK,
ERST20C-VM2CR2.UK,
ERST20C-MECR2.UK,
ERST20D-VM2CR2.UK and
ERST20D-MECR2.UK in
REVISED EDITION-C.
• Some descriptions have been
modified.
OCH570 REVISED EDITION-B
is void.

CONTENTS

1. REFERENCE MANUAL ................................... 3
2. SAFETY PRECAUTION ................................... 4
3. SPECIFICATIONS ............................................ 7
4. PART NAMES AND FUNCTIONS ................. 11
5. OUTLINES AND DIMENSIONS ..................... 13
6. WIRING DIAGRAM ........................................ 15
7. FIELD WIRING ............................................... 34
8. WATER SYSTEM DIAGRAM ......................... 38
9. CONTROLS ................................................... 42
10. TROUBLESHOOTING ................................... 62
11. DISASSEMBLY PROCEDURE ...................... 79
13. SERVICE AND MAINTENANCE ................. 103
PARTS CATALOG (OCB570)
September 2016
No. OCH570
REVISED EDITION-C

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Summary of Contents for Mitsubishi EHST20C-VM2C

  • Page 1: Service Manual

    CYLINDER UNIT September 2016 No. OCH570 SERVICE MANUAL REVISED EDITION-C R410A [Model Name] Revision: EHST20C-VM2C • Added EHST20C-VM2CR2.UK, EHPT20X-VM2C EHST20C-VM6CR2.UK, EHST20C-VM6C EHPT20X-VM6C EHST20C-YM9CR2.UK, EHST20C-TM9CR2.UK, EHST20C-YM9C EHPT20X-YM9C EHST20C-VM2ECR2.UK, EHST20C-VM6ECR2.UK, EHST20C-TM9C EHPT20X-TM9C EHST20C-YM9ECR2.UK, EHST20C-VM2EC EHPT20X-MHCW EHST20C-MHCWR2.UK, EHST20C-MECR2.UK, EHST20C-VM6EC ERST20C-VM2C EHST20D-VM2CR2.UK, EHST20D-VM2ECR2.UK, EHST20C-YM9EC ERST20C-MEC EHST20D-YM9CR2.UK,...
  • Page 2 [Service Ref.] EHST20C-VM2CR1.UK EHST20C-VM2CR2.UK EHST20C-VM2C.UK EHST20C-VM6CR2.UK EHST20C-VM6CR1.UK EHST20C-VM6C.UK EHST20C-YM9CR1.UK EHST20C-YM9CR2.UK EHST20C-YM9C.UK EHST20C-TM9CR1.UK EHST20C-TM9CR2.UK EHST20C-TM9C.UK EHST20C-VM2ECR1.UK EHST20C-VM2ECR2.UK EHST20C-VM2EC.UK EHST20C-VM6ECR1.UK EHST20C-VM6ECR2.UK EHST20C-VM6EC.UK EHST20C-YM9ECR2.UK EHST20C-YM9ECR1.UK EHST20C-YM9EC.UK EHST20C-MHCWR1.UK EHST20C-MHCWR2.UK EHST20C-MHCW.UK EHST20C-MECR1.UK EHST20C-MECR2.UK EHST20C-MEC.UK EHST20D-VM2CR1.UK EHST20D-VM2CR2.UK EHST20D-VM2C.UK EHST20D-VM2ECR1.UK EHST20D-VM2ECR2.UK EHST20D-VM2EC.UK EHST20D-YM9CR1.UK EHST20D-YM9CR2.UK EHST20D-YM9C.UK EHST20D-MHCWR1.UK EHST20D-MHCWR2.UK EHST20D-MHCW.UK...

  • Page 3: Reference Manual

    REFERENCE MANUAL OUTDOOR UNIT'S SERVICE MANUAL Service Ref. Service Manual No. PUHZ-W50/85VHA(-BS) PUHZ-W50/85VHAR1(-BS) OCH439 PUHZ-W50VHAR2(-BS) PUHZ-W50VHAR3(-BS) PUHZ-W50VHA2(-BS) OCH605 PUHZ-W50VHA2R1(-BS) PUHZ-W85VHA2(-BS).UK PUHZ-W85VHA2R1(-BS).UK PUHZ-W85VHA2R3(-BS).UK OCH465 PUHZ-W85VHA2R4(-BS).UK PUHZ-W85VHA2R5(-BS).UK PUHZ-W112VHA(-BS) OCH562 PUHZ-W112VHAR1(-BS) PUHZ-HW112/140YHA(-BS) PUHZ-HW112/140YHA2(-BS) PUHZ-HW112/140YHA2R1(-BS) PUHZ-HW112/140YHA2R3(-BS) PUHZ-HW112/140YHA2R4(-BS) PUHZ-HW112/140YHA2R5(-BS) PUHZ-HW140VHA(-BS) OCH439 PUHZ-HW140VHA2(-BS) PUHZ-HW140VHA2R1(-BS) PUHZ-HW140VHA2R2-BS PUHZ-HW140VHA2R3(-BS) PUHZ-HW140VHA2R4(-BS) PUHZ-HW140VHA2R5(-BS) PUHZ-SW40/50VHA(-BS)

  • Page 4: Refer To

    Precautions that must be observed to prevent damage to unit. This installation manual along with the user manual should be left with the product after installation for future reference. Mitsubishi Electric is not responsible for the failure of locally-supplied parts. • Be sure to perform periodical maintenance.
  • Page 5 WARNING (SPLIT MODELS ONLY) Do not discharge refrigerant into the atmosphere if refrigerant leaks during installation, ventilate the room. Use appropriate tools for high pressure refrigerant. When pumping down refrigerant, stop the compressor before disconnecting the refrigerant pipes. During installation securely fasten the refrigerant pipes before starting the compressor. Check that refrigerant gas does not leak after the completion of installation. Use R410A refrigerant only. Do not allow air to enter the lines. Failure to observe these instructions will cause mechanical failure, system failure or, in the worst case, serious breach of product safety. CAUTION (SPLIT MODELS ONLY) <Using R410A refrigerant heat pumps> Use C1220 copper phosphorus, for copper and copper alloy seamless pipes, to connect the refrigerant pipes. Make sure the insides of the pipes are clean and do not contain any harmful contaminants such as sulfuric compounds, oxidants, debris, or dust. Use pipes with the specified thickness. (Refer to section 4.4 in the installation manual.) Note the following if reusing existing pipes that carried R22 refrigerant. - Replace the existing flare nuts and flare the flared sections again. - Do not use thin pipes. (Refer to section 4.4 in the installation manual.) Store the pipes to be used during installation indoors and keep both ends of the pipes sealed until just before brazing. (Leave elbow joints, etc. in their packag- ing.) If dust, debris, or moisture enters the refrigerant lines, oil deterioration or compressor breakdown may result.
  • Page 6 [1] Cautions for service (1) Perform service after recovering the refrigerant left in unit completely. (2) Do not release refrigerant in the air. (3) After completing service, charge the cycle with specified amount of refrigerant. (4) If moisture or foreign matter might have entered the refrigerant piping during service, ensure to remove them. [2] Additional refrigerant charge When charging directly from refrigerant cylinder (1) Check that cylinder for R410A on the market is syphon type.

  • Page 7: Specifications

    SPECIFICATIONS OCH570C...
  • Page 8 OCH570C...
  • Page 9 OCH570C...
  • Page 10 OCH570C...

  • Page 11: Part Names And Functions

    <EH*T20*-MHCW> <EHST20*-*M**C*> (UK split / packaged model system) (Split model system) <EHPT20X-*M**C*> (Packaged model system) PART NAMES AND FUNCTIONS <EH*T20*-MHCW> <EH*T20*-MHCWR1> <E*ST20*-*M**C> (UK split/packaged model system) <E*ST20*-*M**CR1> (Split model system) <EHPT20X-*M**C*> <EHPT20X-*M**C*R1> (Packaged model system) <Figure 4-1> E*ST20*- E*ST20*- EHPT20X- EHPT20X- EHST20*- E*ST20*-MEC EHST20D-MHC...
  • Page 12 <EH*T20*-MHCWR2> <E*ST20*-*M**CR2> (UK split/packaged model system) (Split model system) <EHPT20X-*M**C*R2> (Packaged model system) <Figure 4-2> E*ST20*- E*ST20*- E*ST20*- EHST20D- EHPT20X- EHPT20X- EHST20*- Part name *M2/6/9CR2 *M2/6/9ECR2 MECR2 MHCR2 *M2/6/9CR2 MHCWR2 MHCWR2 DHW outlet pipe Cold water inlet pipe Water pipe (Space heating/cooling return connection) Water pipe (Space heating/cooling flow connection) Water pipe (Flow from heat pump connection) —...

  • Page 13: Outlines And Dimensions

    OUTLINES AND DIMENSIONS 5-1. Technical Drawings <Unit: mm> <E**T20*-*M**C> <ERST20*-*M**C> Pressure relief valve Pressure relief valve (Primary circuit) (Sanitary circuit) Air vent G1/2 G1/2 Main remote controller Terminal block Front panel <Left side> <Front> <Right side> <Front> Optional part (PAC-DP01-E) 67.8 127.8 342.3 402.3...

  • Page 14: Cylinder Unit

    5-2. Service access diagrams Service access * An additional 300 mm of space (total Parameter Dimension (mm) 600 mm) is required , when installing 300* the optional 2-zone kit (PAC-TZ01-E) on top of the cylinder unit. c (distance behind unit not visible in the right figure) Sufficient space MUST be left for the provision of discharge pipework as detailed in National and Local Building Regulations. The cylinder unit must be located indoors and in a frost-free environment, for example in a utility room, to minimise heat loss from stored water.

  • Page 15: Wiring Diagram

    WIRING DIAGRAM 6-1. EHST20C-VM2C.UK, EHST20C-VM2EC.UK, EHST20D-VM2C.UK, EHPT20X-VM2C.UK, EHST20D-VM2EC.UK, ERST20C-VM2C.UK, ERST20D-VM2C.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4>...
  • Page 16 6-2. EHST20C-VM2CR1.UK, EHST20C-VM2ECR1.UK, EHST20D-VM2CR1.UK, EHPT20X-VM2CR1.UK, EHST20D-VM2ECR1.UK, ERST20C-VM2CR1.UK, ERST20D-VM2CR1.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit ~/N 230V 50Hz unit <How to use TBO.1 to 4> to Booster heater Power supply Connect them using either way as shown below.
  • Page 17 6-3. EHST20C-VM2CR2.UK, EHST20C-VM2ECR2.UK, EHST20D-VM2CR2.UK, EHPT20X-VM2CR2.UK, EHST20D-VM2ECR2.UK, ERST20C-VM2CR2.UK, ERST20D-VM2CR2.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 18 6-4. EHST20C-VM6C.UK, EHST20C-VM6EC.UK, EHPT20X-VM6C.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor Power supply To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 19 6-5. EHST20C-VM6CR1.UK, EHST20C-VM6ECR1.UK, EHPT20X-VM6CR1.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit ~/N 230V 50Hz unit <How to use TBO.1 to 4> to Booster heater Power supply Connect them using either way as shown below.
  • Page 20 6-6. EHST20C-VM6CR2.UK, EHST20C-VM6ECR2.UK, EHPT20X-VM6CR2.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 21 6-7. EHST20C-YM9C.UK, EHST20C-YM9EC.UK, EHPT20X-YM9C.UK, EHST20D-YM9C.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit unit Power supply <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply to Booster heater Connect them using either way as shown below.
  • Page 22 6-8. EHST20C-YM9CR1.UK, EHST20C-YM9ECR1.UK, EHPT20X-YM9CR1.UK, EHST20D-YM9CR1.UK Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor Power supply To outdoor Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Power supply to Booster heater Connect them using either way as shown below.
  • Page 23 6-9. EHST20C-YM9CR2.UK, EHST20C-YM9ECR2.UK, EHPT20X-YM9CR2.UK, EHST20D-YM9CR2.UK Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor Power supply To outdoor Immersion heater (1Ph3kW)(Option) <How to use TBO.1 to 4> unit ~/N 230V 50Hz unit Power supply Power supply to Booster heater Connect them using either way as shown below.
  • Page 24 6-10. EHST20C-TM9C.UK, EHPT20X-TM9C.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 25 6-11. EHST20C-TM9CR1.UK, EHPT20X-TM9CR1.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 26 6-12. EHST20C-TM9CR2.UK, EHPT20X-TM9CR2.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor Power supply To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz to Booster heater Power supply Connect them using either way as shown below.
  • Page 27 6-13. EHST20C-MEC.UK, EHST20D-MEC.UK, ERST20C-MEC.UK, ERST20D-MEC.UK, EHST20D-MHC.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Connect them using either way as shown below.
  • Page 28 6-14. EHST20C-MECR1.UK, EHST20D-MECR1.UK, EHST20D-MHCR1.UK, ERST20C-MECR1.UK, ERST20D-MECR1.UK Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Connect them using either way as shown below.
  • Page 29 6-15. EHST20C-MECR2.UK, EHST20D-MECR2.UK, EHST20D-MHCR2.UK, ERST20C-MECR2.UK, ERST20D-MECR2.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW)(Option) unit ~/N 230V 50Hz unit <How to use TBO.1 to 4> Power supply Connect them using either way as shown below.
  • Page 30 6-16. EHPT20X-MHCW.UK, EHST20C-MHCW.UK, EHST20D-MHCW.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Connect them using either way as shown below. to Immersion heater ~/N 230V 50Hz Tool...
  • Page 31 6-17. EHPT20X-MHCWR1.UK, EHST20C-MHCWR1.UK, EHST20D-MHCWR1.UK Indoor unit powered Indoor unit powered via outdoor unit by independent source To outdoor Power supply To outdoor Immersion heater (1Ph3kW) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Connect them using either way as shown below. to Immersion heater ~/N 230V 50Hz Tool...
  • Page 32 6-18. EHPT20X-MHCWR2.UK, EHST20C-MHCWR2.UK, EHST20D-MHCWR2.UK Indoor unit powered Indoor unit powered by independent source via outdoor unit To outdoor To outdoor Power supply Immersion heater (1Ph3kW) unit unit <How to use TBO.1 to 4> ~/N 230V 50Hz Power supply Connect them using either way as shown below. to Immersion heater ~/N 230V 50Hz Tool...
  • Page 33 6-19. DIP switch functions Located on the FTC printed circuit board are 4 sets of small white switches known as DIP switches. The DIP switch number is printed on the circuit board next to the relevant switches. The word ON is printed on the circuit board and on the DIP switch block itself. To move the switch you will need to use a pin or the corner of a thin metal ruler or similar. DIP switch settings are listed below in the table below. Only an authorised installer can change DIP switch setting under one's own re- sponsibility according to the installation condition. Before changing any switch settings, ensure power supplies to indoor and out- door units are isolated/powered off. Default settings: DIP switch Function Indoor unit model SW1 SW1-1 Boiler WITHOUT Boiler WITH Boiler...

  • Page 34: Field Wiring

    FIELD WIRING Breaker abbreviation Meaning ECB1 Earth leakage circuit breaker for booster heater ECB2 Earth leakage circuit breaker for immersion heater Terminal block 1 Option 1: Cylinder unit powered via outdoor unit <1 phase> Affix label A that is included with the manuals near each Cylinder unit wiring diagram for cylinder unit and outdoor units. Outdoor unit Wiring Earth circuit To control leakage breaker board circuit Power breaker supply Isolating...
  • Page 35 <3 phase> Affix label A that is included with the manuals near each wiring diagram for cylinder unit and outdoor units. Cylinder unit Outdoor unit To control board Wiring Earth circuit leakage Power breaker circuit supply breaker Isolating 400 V switch 50 Hz ECB1 Wiring booster circuit Power supply heater breaker (Primary circuit) 3~ 400 V 50 Hz (EH*T20*-YM*C) Isolating 3~ 230 V 50 Hz (EH*T20*-TM*C) If the installed earth leakage circuit breaker switch does not have an over-current protection...
  • Page 36 Option 2: Cylinder unit powered by independent source. If the cylinder unit and outdoor unit have separate power supplies, the following requirements MUST be carried out: Initial settings White (Power supplied by CN01 outdoor unit) • Change the interconnected wiring in the control and electrical box of the Cylinder unit cylinder unit (see Figure 7-3). control board • Turn the outdoor unit DIP switch SW8-3 to ON. • Turn on the outdoor unit BEFORE the cylinder unit. • Power by independent source is not available for particular models of outdoor unit model. For more detail, refer to the connecting outdoor unit Installation Manual. Modified settings (Separate power White...
  • Page 37 <3 phase> Affix label B that is included with the manuals near each wiring diagram for cylinder unit and outdoor units. Cylinder unit Wiring Earth circuit leakage breaker Power circuit To control supply board breaker Isolating switch 230 V 50 Hz Outdoor unit Wiring Earth circuit leakage Power breaker circuit supply breaker...

  • Page 38: Water System Diagram

    WATER SYSTEM DIAGRAM • Refer to <Table 4-1 and 4-2> for the part names. *1 Refer to the following section [Local system]. <E*ST20*-*M**C > (Split model system) Refrigerant pipe Water pipe Cold water Notes: Drain • To enable draining of the cylinder unit an isolating valve should be posi- tioned on both the inlet and outlet pipework. Local system • Be sure to install a strainer on the inlet pipework to the cylinder unit.
  • Page 39 307 kg 320 kg 312 kg Maximum primary working pressure 2.5 bar 2.5 bar 2.5 bar * E N60335/Type 3000W single phase 230V 50Hz, length 460 mm. Use only Mitsubishi Electric service parts as a direct replacement. <Table 8-1> <EHPT20X-*M*C> (Packaged model system) Water pipe Cold water Drain Notes: • To enable draining of the cylinder unit an isolating valve should be po-...
  • Page 40 Local system 1-zone temperature control Zone1 Zone1 2-zone temperature control 1-zone temperature control with boiler Zone1 Zone1 Zone2 2-zone temperature control with boiler 1-zone temperature control (2-zone valve ON/OFF control) Zone1 Zone1 Zone2 Zone2 1. Z one1 heat emitters (e.g. radiator, fan coil unit) (local supply) 10. Zone2 water circulation pump (local supply) 2.
  • Page 41 Filling the cylinder unit (Primary circuit) 1. Check and charge expansion vessel. 2. Check all connections including factory fitted ones are tight. 3. Insulate pipework between cylinder unit and outdoor unit. 4. Thoroughly clean and flush, system of all debris. (Refer to 4.2 in the installation manual.) 5. Fill cylinder unit with potable water. Fill primary heating circuit with water and suitable anti-freeze and inhibitor as necessary. Always use a filling loop with double check valve when filling the primary circuit to avoid back flow contamination of water supply. • Anti-freeze should always be used for packaged model systems. It is the responsibility of the installer to decide if anti-freeze solution should be used in split model systems depending on each site’s conditions. Corrosion inhibitor should be used in both split model and packaged model systems. Figure below shows freezing temperature against anti-freeze concentration. This figure is an example for FERNOX ALPHI-11. For other anti-freeze, please refer to relevant manual. • When connecting metal pipes of different materials insulate the joints to prevent a corrosive reaction taking place which will damage the pipework. 6. C heck for leakages. If leakage is found, retighten the nut onto the connections. 7. Pressurise system to 1 bar. 8. Release all trapped air using air vents during and following heating period.

  • Page 42: Controls

    CONTROLS 9-1. Main remote controller <Main remote controller parts> Letter Name Function Screen Screen in which all information is displayed Menu Access to system settings for initial set up and modifications. Back Return to previous menu. Confirm Used to select or save. (Enter key) Power/Holiday If system is switched off pressing once will turn system on. Pressing again when system is switched on will enable Holiday Mode. Holding the button down for 3 seconds will turn the system off. (*1) F1-4 Function keys Used to scroll through menu and adjust settings.
  • Page 43 9-2. Setting the Main remote controller After the power has been connected to the outdoor and cylinder units (See "7. FIELD WIRING") the initial system settings can be entered via the main remote con- troller. 1. Check all breakers and other safety devices are correctly installed and turn on power to the system. 2. When the main remote controller is switched on for the first time, the screen automatically goes to Initial settings menu, Language setting screen and Date/Time setting screen in order. 3. Main remote controller will automatically start up. Wait approximately 6 minutes whilst the control menus load. 4. When the controller is ready a blank screen with a line running across the top will be displayed. 5. Press button E (Power) (refer to page 42) to turn on the system. Before turning on the system, perform initial settings as instructed below. 9-3. Main Settings Menu The main settings menu can be accessed by pressing the MENU button. To reduce the risk of untrained end users altering the settings accidentally there are 2 access levels to the main settings; and the service section menu is password protected. User Level – Short press If the MENU button is pressed once for a short time the main settings will be displayed but without the edit function. This will enable the user to view current settings but NOT change the parameters. Installer Level – Long press If the MENU button is pressed down for 3 seconds the main settings will be dis- played with all functionality available.
  • Page 44 <Main Remote Controller Menu Tree> Initial Unrestricted access Installer only Main screen * Short press for 1 Zone system. Information Long press Option Forced DHW ON ( )/OFF ON ( )/Prohibited ( )/Timer ( ) Heating/Cooling ON ( )/Prohibited ( )/Timer ( ) Consumed electrical energy Menu Delivered energy...
  • Page 45 <Continued from the previous page.> <Main Remote Controller Menu Tree> Unrestricted access Initial Installer only Main Main screen menu Long press Manual operation Menu Function settings Service Thermistor adjustment Password ON/OFF protected Economy settings Delay <See section> for pump ON/OFF Electric heater (Heating) Delay ON/OFF (Booster heater/Immersion heater) Auxiliary settings Electric heater (DHW) Delay Running...
  • Page 46 9-4. Service Menu The service menu provides functions for use by installer or service engineer. It is NOT intended the home owner alters settings within this menu. It is for this reason password protection is required to prevent unauthorised access to the service settings. The factory default password is "0000". Follow the procedure described in General Operation for the set up operation. The service menu is navigated using the F1 and F2 buttons to scroll through the functions. The menu is split across 2 screens and is comprised of the following functions; 1. Manual operation 2. Function settings 3. Thermistor adjustment 4. Auxiliary settings 5. Heat source setting 6. Pump speed 7. Operation settings 8. Energy monitor settings 9. External input settings 10. Running information 11. Thermistor reading 12. Summary of settings 13. Error history 14. Password protection 15. Manual reset 16.
  • Page 47 <Thermistor adjustment> This function allows adjustments to be made to the thermistor readings from −10 to 10°C in 0.5°C intervals. THW1: Thermistor (Flow water temp.) THW2: Thermistor (Return water temp.) THW5: Thermistor (DHW tank water temp.) THW6: Thermistor (Zone1 flow temp.)(Option) THW7: Thermistor (Zone1 return temp.)(Option) THW8: Thermistor (Zone2 flow temp.)(Option) THW9: Thermistor (Zone2 return temp.)(Option) THWB1: Thermistor (Boiler flow temp.)(Option) THWB2: Thermistor (Boiler return temp.)(Option) ▼ ▲ <Auxiliary settings> This function is used to set the parameters for any auxiliary parts used in the system Menu subtitle Function/ Description Economy settings for Water pump stops automatically in certain period of time from pump...
  • Page 48 Mixing valve control 1. From the Auxiliary settings menu highlight Mixing valve control. 2. Press CONFIRM. 3. The Mixing valve control screen is displayed. 4. U se F1 and F2 buttons to set Running time between 10 to 240 seconds. The Running time equals to a period from full open of the valve (at a hot water mixing ratio of 100%) to full close (at a cold water mixing ratio of 100%). Note: Set the Running time according to the specifications of the actuator of each mixing valve. 1. From the Auxiliary settings menu highlight Mixing valve control. 2. Press CONFIRM. Mixing valve control setting screen 3. The Mixing valve control screen is displayed. 4. P ress F3 and F4 buttons to set the interval between 2-zone temperature controls of the mixing valve between 1 to 30 minutes.
  • Page 49 <Operation settings> Heating operation This function allows operational setting of flow temperature range from the Ecodan and also the time interval at which the FTC collects and processes data for the auto adaptation mode. Menu subtitle Function Range Unit Default Flow temp. range Minimum temp. To minimize the loss by frequent ON and OFF in mild outdoor ambient tem- 25–45 ºC perature seasons. Maximum temp. To set max. possible flow temperature according to the type of heat emitters. 35–60 ºC Room temp. control Mode Setting for Room temp. control Normal/ — Normal At Fast mode, target outlet water temperature is set higher than the one set Fast at normal mode. This reduces the time to reach the target room temperature when the room temperature is relatively low.* Interval Selectable according to the heat emitter type and the materials of floor (i.e. 10–60 radiators, floor heating-thick, -thin concrete, wood, etc.) Heat pump thermo diff.adjust ON/OFF...
  • Page 50 Set the electric heater capacity and water pump(s) input according to indoor unit model and specs of additional pump(s) supplied locally. (Refer to the menu tree in “9-3. Main Settings Menu”) Immersion Booster heater1 Booster heater2 Pump1 Pump2 Pump3 heater Default 2 kW 4 kW ***(factory fitted pump) EHST20C-VM2C 2 kW EHST20C-VM6C 2 kW 4 kW EHST20C-YM9C 3 kW 6 kW EHST20C-TM9C 3 kW 6 kW EHST20C-VM2EC 2 kW EHST20C-VM6EC...
  • Page 51 2. Settings using the main remote controller In this menu, all parameters required to record the consumed electrical energy and the delivered heat energy which is displayed on the main remote controller can be set. The parameters are an electric heater capacity, supply power of water pump and heat meter pulse. Follow the procedure described in General Operation for the set up operation. For Pump 1, *** can be also set besides this setting. In the case *** is selected, the system acknowledges "factory fitted pump" is selected. Energy monitor settings menu screen <External input settings> Demand control(IN4) The selection of “OFF”, whilst a signal is being sent to IN4, forcefully stops all the heat source operations and the selection of “Boiler” stops operations of heat pump and electric heater and performs boiler operation. Outdoor thermostat (IN5) External input settings menu screen The selection of “Heater”, whilst a signal is being sent to IN5, performs electric-heater-only operation and the selection of “Boiler”...
  • Page 52 <Summary of settings> This function shows the current installer/user entered settings. Abbreviation Explanation Abbreviation Explanation HWtemp DHW max. temperature Z2 mode Operation mode HWdrop DHW temperature drop - HER (Heating room temperature) HWtime DHW max. operation time - HE (Heating flow temperature) NO HW DHW mode restriction - HCC (Heating compensation curve) HWset DHW operation mode (Normal/Eco) - COR (—) - CO (Cooling flow temperature) Ltemp Legionella hot water temperature Hroom 1 Heating target room temperature Lfreq Legionella operation Frequency...
  • Page 53 Resetting the password If you forget the password you entered, or have to service a unit somebody else installed, you can reset the password to the factory default of 0000. 1. F rom the main settings menu scroll down the functions until Service Menu is highlighted. 2. Press CONFIRM. 3. You will be prompted to enter a password. 4. Hold down buttons F3 and F4 together for 3 seconds. 5. Y ou will be asked if you wish to continue and reset the password to default set- ting. 6. To reset press button F3. 7. The password is now reset to 0000. Completion screen <Manual reset> Should you wish to restore the initial settings at any time you should use the man- ual reset function. Please note this will reset ALL functions to the factory default settings. 1. F rom the service menu use F1 and F2 buttons to scroll through list until Manual Reset is highlighted.
  • Page 54 <Table 9-4-1> Request Request content Range Unit code Error history 1 (latest) Displays error history. ("– –" is displays if no history is present.) Code Error history 2 (second to last) Displays error history. ("– –" is displays if no history is present.) — Error history 3 (third to last) Displays error history. ("– –" is displays if no history is present.) — Water circulation pump 1 - Accumulated operating time (after reset) 0–9999 10 hours Water circulation pump 2 - Accumulated operating time (after reset) 0–9999 10 hours Water circulation pump 3 - Accumulated operating time (after reset) 0–9999 10 hours Water circulation pump 4 - Accumulated operating time (after reset) 0–9999...
  • Page 55 Indoor unit switch setting display (Request code: 162 to 166) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4, SW5 SW1, SW2, SW3, SW4, SW5 Display Display 00 00 00 40 00 01 00 41 00 02 00 42 00 03 00 43...
  • Page 56 Indoor unit switch setting display (Request code: 162 to 166) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4, SW5 SW1, SW2, SW3, SW4, SW5 Display Display 00 80 00 C0 00 81 00 C1 00 82 00 C2 00 83 00 C3...
  • Page 57 Output signal display (Request code: 175/553) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx 40 xx 00 xx 41 xx 01 xx 42 xx 02 xx 43 xx 03 xx 44 xx 04 xx 45 xx 05 xx 46 xx 06 xx 47 xx 07 xx 48 xx 08 xx 49 xx 09 xx 4A xx 0A xx 4B xx 0B xx 0C xx 4C...
  • Page 58 Output signal display (Request code: 175/553) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx C0 xx 80 xx C1 xx 81 xx C2 xx 82 xx C3 xx 83 xx C4 xx 84 xx C5 xx 85 xx C6 xx 86 xx C7 xx 87 xx C8 xx 88 xx C9 xx 89 xx CA xx 8A xx CB xx 8B xx CC xx 8C...
  • Page 59 0: OFF 1: ON Output signal display (Request code: 175/553) Display Please refer to Table 2 on relevant wiring diagram whilst using the following. 40 xx 41 xx 0: OFF 1: ON 42 xx 43 xx Display 44 xx 00 xx 45 xx 01 xx 46 xx 02 xx 47 xx 03 xx 48 xx 04 xx 49 xx 05 xx 4A xx 06 xx 4B xx 07 xx 4C xx 08 xx 4D xx 09 xx 4E xx 0A xx...
  • Page 60 Input signal display (Request code: 176/554) Please refer to Table 1 on relevant wiring diagram whilst using the following. 0: OFF (open) 1: ON (short) 0: OFF (open) 1: ON (short) Display Display 00 00 00 40 00 01 00 41 00 02 00 42 00 03 00 43 00 04 00 44 00 05 00 45 00 06...

  • Page 61: Emergency Operation

    Indoor unit only operation Indoor unit only operation In indoor unit only operation, an operation without connecting outdoor unit is possible. When in Indoor unit only operation the main control has control functions. Indoor unit Necessary Heat pump Not necessary <Heater> Main remote controller Necessary Heating for DHW and space heating is provided by the heater. DIP switch setting Electric heater • Activating indoor unit only operation mode SW4-4 ON, SW4-5 ON To activate indoor unit only operation see the following: Boiler 1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

  • Page 62: Troubleshooting

    TROUBLESHOOTING 10-1. Troubleshooting <Summary of self diagnosis based on Error Codes and Service Procedures> Present and past Error codes are logged and displayed on the main remote controller or control board of the outdoor unit. Please refer to the table below and subsequent explanations to diagnose and remedy typical problems that may occur in the field. Unit Condition Error Code Action Reoccurring problem Displayed Use table "10-4. Self diagnosis and action" to identify fault and correct. Not Displayed Use table "10-5. Troubleshooting by inferior phenomena" to identify fault and correct. Non reoccurring problem Logged 1. C heck temporary causes of defects such as the operation of safety devices on the refrigerant/water circuit including compressor, poor wiring, electrical noise, etc. Re-check the symptom and the instal- lation environment, refrigerant amount (Split systems only), weather conditions at time of fault, etc. 2. R eset Error code logs, Service the unit and restart system. Not Logged 1. Recheck the abnormal symptom 2. I dentify cause of problem and take corrective action according to Table "10-5. Troubleshooting by inferior phenomena".
  • Page 63 10-4. Self diagnosis and action Check if DIP SW is set correctly. (Refer to "6-19. DIP switch functions".) Error code Title and display conditions Possible Cause Diagnosis and action Circulation water temperature overheat Insufficient system head Refer to table in "10-6. Checking Com- protection ponent Parts' Function" to determine if <DHW/Heating/Cooling/LP/FS/OS> system pump meets requirements. Error code displayed when THW1 detects a If more head required either add a pump temp. ≥ 80ºC for 10 consecutive seconds or of the same size or replace existing pump THW2 detects a temp. ≥ 80ºC for 10 consecutive with capacity model.
  • Page 64 Error code Title and display conditions Possible Cause Diagnosis and action P1/P2/L5/LD Indoor unit temperature thermistor failure Connector/terminal wire has become Visually check the terminals and connec- Note: The thermistors subject to failure can be detached or loose wiring. tions and reattaches appropriate. checked in “Request code: 567” in Thermistor fault Check resistance of thermistor against “Running information. table in "10-6. Checking Component Parts' Function".
  • Page 65 Error code Title and display conditions Possible Cause Diagnosis and action Heating operation error THW1 has become detached from its Visually inspect location and reattach as Note: “3” is displayed in “Request code: 567” in holder. necessary. “Running information”. <Heating/FS> Booster heater fault Electrically test to determine fault.
  • Page 66 Error code Title and display conditions Possible Cause Diagnosis and action Low primary circuit (Zone2 side) flow rate Insufficient system head If more head required either add a pump of detected by flow switch the same size or replace existing pump. Reduced flow in primary water circuit Check circulation pump (See "10-6. Note: “3” is displayed in “Request code: 569” in Checking Component Parts' Function" for Due to 1 or more of the following; “Running information”. how to check). Faulty pump, insufficient air purge, Open purge valve to remove trapped air.
  • Page 67 Error code Title and display conditions Possible Cause Diagnosis and action E0/E4 Main remote controller communication failure 1. Contact failure with transmission cable 1. Check connection cable for damage or (Reception error) loose connections at the FTC and main Error code E0 is displayed if main remote control- remote controller terminals. ler does not receive any signal from the indoor 2.
  • Page 68 Error code Title and display conditions Possible Cause Diagnosis and action Indoor unit/wireless receiver communication 1. Connection fault with wireless receiver- 1. Check the connections to the wireless re- failure FTC connection ceiver and FTC have not become loose and Error code J0 is displayed when the FTC cannot that the connecting cable is not damaged. receive data from the wireless receiver for 1 2. to 4. 2.
  • Page 69 10-5. Troubleshooting by inferior phenomena Fault symptom Possible cause Explanation - Solution Main remote controller 1. There is no power supply to main remote 1. Check LED2 on FTC. (See "6. WIRING DIAGRAM".) display is blank. controller. (i) When LED2 is lit. Check for damage or contact failure of the main remote controller wiring. (ii) When LED2 is blinking. Refer to No. 5 below. (iii) When LED2 is not lit. Refer to No. 4 below. 2. Power is supplied to main remote 2.
  • Page 70 6. Check resistance across the thermal cut-out, if open then the connection is tripped and cannot be reset using the manual broken and the booster heater will have to be replaced. reset button. Contact your Mitsubishi Electric dealer. 7. Immersion heater cut-out tripped. 7. Check immersion heater thermostat and press reset button, located on im- mersion heater boss, if safe. If the heater has been operated with no water inside it may have failed, so please replace it with a new one.
  • Page 71 4. The booster heater thermal cut-out has 4. Check resistance across the thermal cut-out, if open then connection is bro- tripped and cannot be reset using the manual ken and the booster heater will have to be replaced. reset button. Contact your Mitsubishi Electric dealer. 5. Immersion heater cut-out has been triggered. 5. Check immersion heater thermostat and press reset button located on im- mersion heater boss, if safe. If the heater kept running with no water inside, this may have resulted in failure, so replace it with a new one.
  • Page 72 Fault symptom Possible cause Explanation - Solution In 2-zone tempera- When Zone1 and Zone2 are both in heating Normal action no action necessary. ture control, only mode, the hot water temperature in Zone2 Zone2 does not does not exceed that in Zone1. reach the set tem- Faulty wiring of motorized mixing valve Refer to installation manual, "5.3 Wiring for 2-zone temperature control". perature. Faulty installation of motorized mixing valve Check for correct installation. (Refer to the manual included with each motor- ized mixing valve.) Incorrect setting of Running time Check for correct setting of Running time. Motorized mixing valve failure Inspect the mixing valve. (Refer to the manual included with each motorized mixing valve.)
  • Page 73 Fault symptom Possible cause Explanation - Solution Water discharges from If continual – field supplied pressure Check function of pressure reducing valve and replace if necessary. expansion relief valve reducing valve not working. - part of Inlet Control If continual – expansion relief valve may be Turn the handle on the expansion relief valve to check for foreign objects Group damaged. inside. If the problem is not still solved, replace the expansion relief valve (EH*T20*-MHCW only) with a new one. (sanitary circuit) If intermittent – expansion vessel charge Check gas-side pressure in expansion vessel. may have reduced/bladder perished. Recharge to correct precharge pressure if necessary. If bladder perished replace expansion vessel with a new one with appropriate precharge.
  • Page 74 4. FTC board failure 4. Check the FTC control board. • Check for faulty wiring. • I f no problem found with the wiring, the FTC control board is faulty. Replace the board. Smart grid ready input (IN11 and IN12) is used, Normal operation no action necessary. 35 Heat pump is forced to and switch-on and off commands are input. turn ON and OFF. Annual Maintenance It is essential that the cylinder unit is serviced at least once a year by a qualified individual. Any spare parts required should be purchased from Mitsubishi Electric. NEVER bypass safety devices or operate the unit without them being fully operational. <Annual maintenance points> Use the Annual Maintenance Log Book as a guide to carrying out the necessary checks on the cylinder unit and outdoor unit. OCH570C...
  • Page 75 10-6. Checking component parts' function Part Name Check Points Water circulation pump (primary circuit) <Water circulation pump (primary circuit) characteristics> E*ST20C series 80.0 Speed 5 (Default setting) 70.0 Speed 4 BROWN PWM input signal 60.0 Speed 3 Signal cable BLUE Speed 2 Signal ref. 50.0 Speed 1 BLACK...
  • Page 76 Part Name Check Points Flow sensor Flow signal Flow signal V 5V DC CN1A 0.35V Flow [l/min] Booster heater Measure the resistance between the terminals with a tester. Thermostat (90°C) and thermal cut out (121°C) Terminal Normal Abnormal 121 °C 90 °C 9–10 110(±35) mΩ Open or Short Thermal Manual reset water cut-out thermostat 2 kW heater (230 V, 1 phase) Terminal Normal Abnormal...
  • Page 77 Part Name Check Points 3-way valve (1) Check the movement of the red indicator. The red indicator normally points <DHW> <Heating> to A in DHW mode and to B in Heating mode as shown to the left. (2) I f each indicator position is correct but the 3-way valve does not work prop- Motor erly, the motor may not fit onto the valve securely, so remove the motor by pressing the release button, and reinstall it. Indicator (red) Release button Valve Thermistors Disconnect the connector then measure the resistance with a tester. (At ambient temperatures of 10–30°C.) Thermistor Normal Abnormal THW1 THW2 THW5 4.3–9.5 kΩ...
  • Page 78 10-7. Test point diagram FTC (Controller board) CNP1/OUT1 (TBO.1 1-2) Water circulation pump1 OUT2 (TBO.1 3-4) (230 V AC) Water circulation pump2 (Local supply) (230 V AC) OUT3 (TBO.1 5-6) Water circulation pump3 CN01 (Local supply) (230 V AC) Power supply (230 V AC) CNP4/OUT14 Water circulation pump4...

  • Page 79: Disassembly Procedure

    DISASSEMBLY PROCEDURE <Preparation for the repair service> ● Prepare the proper tools. ● Prepare the proper protectors. ● Provide adequate ventilation. ● After stopping the operation of the cylinder and outdoor unit, turn off all the power-supply breaker. ● Discharge the condenser before the work involving the electric parts. ● Allow parts to cool. ● Do not expose the electric parts to water. ● When replacing or servicing water circuit parts, drain system first. Check individual illustrations and positions of the parts by referring to the parts catalog. Some lead wires and pipes are bundled with bands. Cut the bands to undo the fastened pipes and lead wires if necessary. When bundling the lead wires and pipes again, use new commercially available bands. When removing the parts associated with water pipe work, drain the cylinder unit as necessary. Refer to "Draining the cylinder unit" on page 41. When draining the cylinder unit, keep water from splashing on the internal parts (mainly electric parts and insulations). DISASSEMBLY PROCEDURE PHOTOS 1. How to remove the front panel Photo 1-1 (1) R emove the 2 screws at the bottom of the cylinder unit. Main remote controller (Photo 1-1) (2) S lightly lift and pull out the front panel from the cylinder unit.
  • Page 80 PHOTOS DISASSEMBLY PROCEDURE 3. How to remove the electrical parts Earth leakage circuit Photo 3-1 Control box breakers (ECB1, ECB2) (Step (1) is applied to all the following parts.) (1) Remove the front panel (Refer to Procedure 1). <Earth leakage circuit breaker> (Photo 3-1) (2) D isconnect all the lead wires from the earth leakage cir- Controller board cuit breaker. (3) Remove the 2 screws on the earth leakage circuit breaker.
  • Page 81 PHOTOS DISASSEMBLY PROCEDURE 4. How to remove the control box Photo 4-1 (1) Remove the front panel (Refer to Procedure 1). Cable (2) Disconnect only the lead wires in the control box that Bracket (R) clamps connect to the components in the cylinder unit. Photo 4-2 shows the control box before the related lead Screw wires are disconnected. Screw (3) Remove the 3 screws on the bracket (L and R) and disengage the tab on the control box bracket from the front frame (L).
  • Page 82 DISASSEMBLY PROCEDURE PHOTOS 5. How to remove water pump (primary circuit)/pump valve/ Photo 5-1 strainer valve <Water pump> (1) Remove the front panel (Refer to Procedure 1). Quick connection (2) Disconnect the CNP1 connector, the earth cable and the O-ring CNPWM connector in the control box. (Photo 4-2) (3) R elease the water pump lead wire from the 2 cable clamps, the fastener and the cable strap in the control Strainer valve...
  • Page 83 From the previous page. DISASSEMBLY PROCEDURE PHOTOS Photo 5-5 Cover Strainer mesh (inside) <Strainer valve> (6) Remove the 2 screws on the strainer valve stay. (Photo 5-1) (7) R emove the strainer valve by detaching the quick con- nection. • W hen reinstalling the quick connection, use a new O-ring. • R efer to Procedure 23 for how to attach and detach the quick connection. (8) R emove the strainer valve stay by removing the 2 screws. (Photo 5-5) • R euse the removed strainer valve stay and the strainer valve stay fixing screws. Note: S kip steps (2) and (3) when replacing the strainer Strainer valve stay Screws valve only.
  • Page 84 DISASSEMBLY PROCEDURE PHOTOS 7. How to remove the flow sensor <For R2 models> (1) Remove the front panel (Refer to Procedure 1). (5) Remove the flow sensor by detaching the same (2) Disconnect the CN1A connector on the controller board. diameter quick connection. (Photos 7-3 and 7-4) (Photo 4-2) • W hen reinstalling the flow sensor, use new O-rings.
  • Page 85 EHST20C-YM9C No.1 BHC1-U EHST20C-TM9C No.2 BHC1-V EHST20C-YM9EC No.3 BHC1-W EHPT20X-YM9C No.4 BHC2-U EHPT20X-TM9C No.5 BHC2-V EHST20D-YM9C No.6 BHC2-W EHST20C-VM2C No.1 BHC1-U Terminal EHST20C-VM2EC No.2 BHC1-V CNBHT Cable block (TB1) EHST20D-VM2C connector strap EHST20D-VM2EC The photos shown are of the EHST20C-VM6C model. EHPT20X-VM2C ERST20C-VM2C ERST20D-VM2C Refer to 6. WIRING DIAGRAM Pipe (B.H.-D.V.)
  • Page 86 From the previous page. DISASSEMBLY PROCEDURE PHOTOS Photo 8-3 (3) Remove the DIV frame by removing the 2 screws on it, and Booster heater O-ring remove the cushion by cutting the band. Then remove the rubber by cutting the band. (Photo 8-2) (4) Close (OFF) the pump valve. (Photo 8-2) • W hen the pump valve handle is stiff, use a tool to grip the handle and turn it carefully. • W hen opening or closing the pump valve, ensure to do so fully, not halfway. (5) Detach the 2 quick connections (Inlet of booster heater and outlet of P-HEX) (Photos 8-2 and 8-3) • W hen reinstalling the quick connections, use new O-rings.
  • Page 87 DISASSEMBLY PROCEDURE PHOTOS 9. How to remove the thermostat/immersion heater Photo 9-1 <Thermostat> (1) Remove the front panel (Refer to Procedure 1). (2) P eel off the water-proof tapes on the plastic head of the thermostat in order to reveal the thermostat terminals, and disconnect the lead wires from the terminals. (Photos 9-1 and 9-2) • U se new commercially available water-proof tapes to cover the terminals again.
  • Page 88 DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-1 (Refrigerant - Water) <E*ST20C model> (1) P ump down the refrigerant circuit and close the stop Band DIV frame valve at the outdoor unit side. (Refer to 12. SUPPLEMENTARY INFORMATION.) (2) Remove the front panel (Refer to Procedure 1). (3) Remove the control box (Refer to Procedure 4).
  • Page 89 From the previous page. DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-4 (Refrigerant - Water) (7) Remove the thermistor (TH2) from the thermistor pocket Expansion vessel (Refer to Procedure 20). (8) R emove the manometer with the manometer cover (Refer to Procedure 11). (9) Loosen the flare nuts for Air vent (automatic) and pressure relief valve (3 bar), and remove the Air vent (automatic) and pressure relief valve (3 bar) together with the flare joints. (Refer to Procedure 11)
  • Page 90 From the previous page. DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the plate heat exchanger (P-HEX) Photo 10-8 <E*ST20D model> Pump stay (15) R emove the pump stay by removing the 3 screws on it. (Photo 10-8) (16) R emove the 3 screws on the front frame (L), and 1 screw on the bottom. (Photos 10-8 and 10-9) (17) L oosen the hooks on the plate to pull out the P-HEX with plates from the cylinder unit by lifting them together. (Photos 10-9 and 10-10) (18) R emove the pipe band by removing 2 screws on it, and remove the water coil cover by removing the 2 screws on it.
  • Page 91 DISASSEMBLY PROCEDURE PHOTOS 11. How to remove the pressure relief valve/manometer/air vent (automatic) Photo 11-1 Manometer Manometer (1) Remove the front panel (Refer to Procedure 1). cover (2) Swing the control box to the front (Refer to Procedure 4). <Manometer> (3) R emove the G1/4" nut from the pressure relief valve using 2 spanners: one to hold the joint (G1/4") and the other to turn the manometer connection. (Photo 11-1) • W hen reinstalling the G1/4" nut, use a new G1/4"...
  • Page 92 From the previous page. DISASSEMBLY PROCEDURE PHOTOS 11. How to remove the pressure relief valve/manometer/air Photo 11-5 Air vent vent (automatic) (automatic) Pressure relief valve (3 bar) <Pressure relief valve (3 bar)> (3) R emove the field piping from the pressure relief valve (3 bar). (Photo 11-5) Flare joint (4) R emove the pressure relief valve (3 bar) with the flare Flare joint joint using 2 spanners: one to hold the flare joint and the Flare nut other to turn the flare nut.
  • Page 93 DISASSEMBLY PROCEDURE PHOTOS Photo 12-1 12. How to remove the expansion vessel (1) Remove the front panel (Refer to Procedure 1). Expansion vessel Flare joint Flare nut (2) Swing the control box to the front (Refer to Procedure 4). (3) Remove 2 tapes. (Photo 12-1) • The removed tape can be disposed of. (4) R emove the flare nut using 2 spanners: one to hold the flare joint and the other to turn the flare nut. (Photo 12-1) (5) D isplace the pipe slightly downward and pull out the expansion vessel. (Photo 12-1) (6) R emove the flare joint from the expansion vessel. (Photo Pipe...
  • Page 94 DISASSEMBLY PROCEDURE PHOTOS Drain cock for P-HEX 15. How to remove the drain cock (primary circuit) Photo 15-1 (Pipe side) (1) Remove the front panel (Refer to Procedure 1). <Pump valve side> (2) R emove the drain cock from the pump valve by turning the drain cock. (Photo 15-1) <Pipe side (for P-HEX)>...
  • Page 95 DISASSEMBLY PROCEDURE PHOTOS 17. How to remove the plate heat exchanger (P-HEX) <Water - Water> (1) Remove the front panel (Refer to Procedure 1). (2) D rain water in the P-HEX (Water-Water) using the drain Photo 17-1 cock (Primary circuit) and the drain cock (Sanitary circuit). (Photo 17-1) (3) R emove the 2 screws to remove the water coil W cover.
  • Page 96 DISASSEMBLY PROCEDURE PHOTOS Photo 19-1 19. How to remove the scale trap (sanitary circuit) (1) Remove the front panel (Refer to Procedure 1). (2) Disconnect the CNP4 connector and the earth cable in Nut (G3/4"), the control box. (Photo 4-1) Gasket (G3/4") (3) R elease the water pump lead wire from the 2 cable clamps and the cable strap in the control box, the 2 cable straps and the 3 bands below the control box.
  • Page 97 DISASSEMBLY PROCEDURE PHOTOS 20. How to remove the liquid refrigerant temp. thermistor Thermistor Thermistor Photo 20-1 (TH2)/flow water temp. & return water temp. thermistor <THW5> <THW1> Band (THW1,THW2)/tank water temp. thermistor (THW5) (1) Remove the front panel (Refer to Procedure 1). (2) D isconnect the following thermistor connectors on the controller board and release the lead wires from cable clamps and bands.
  • Page 98 DISASSEMBLY PROCEDURE PHOTOS 21. How to remove the side panels Photo 21-1 (1) Remove the front panel (Refer to Procedure 1). Side panel (Right) (2) Remove the 4 screws on the top panel, and remove the 2 screws that hold the top panel onto the back panel. (Photos 21-2 and 22-1) (3) R emove the side panel (right) by removing the 7 screws fixing the side panel (right). (Photo 21-1) (4) R emove the side panel (left) by removing the 8 screws Side panel fixing the side panel (left). (4 screws on the front side (Left) Screws and 4 screws on the back side) <V/M plate (EH*T20*-MHCW models only)>...
  • Page 99 DISASSEMBLY PROCEDURE PHOTOS 22. How to remove the back panel Photo 22-1 (1) Remove the front panel (Refer to Procedure 1). (2) Remove the side panels (Refer to Procedure 21). Screws (Top panel) Top panel (3) R emove the 4 screws on the back panel, and remove the 2 screws that hold the back panel onto the frame. Then pull out the back panel while lifting the top panel. (Photos 22-1 and 22-2) Note: The handles are removed by pushing them up.
  • Page 100 DISASSEMBLY PROCEDURE PHOTOS & ILLUSTRATION Photo 23-1 23. How to detach and attach the quick connection Refer to the following steps when detaching and attaching the quick connection. (1) Remove the clip. (Photos 23-1 and 23-2) (2) S eparate the connected parts to remove the O-ring. (Photo 23-3) Clip • Do not reuse the removed O-ring. • W ipe off if dirt or foreign matters are found on the sealing surface where the O-ring touches. (3) Apply grease on the O-ring using a plastic bag, etc. (Photo 23-4) (4) A ttach the O-ring to the male part of quick connection. (Pho- Clip to 23-5)
  • Page 101 Notes on replacing the parts Replacement of the parts listed below requires the following procedure. After the parts are removed, eliminate loctite on threads by applying loctite remover, apply new loctite, and then install and tighten the parts to the specified tighten- ing torques below. For details about recommended loctite and loctite remover, refer to Table 11-1, and for details about the replacement parts and their tightening torques, refer to Table 11-2. Table 11-1 Recommended Manufacturer Applied parts Note Loctite Henkel Loctite 577 PRESSURE RELIEF VALVE (3bar Apply loctite all over from the end of external thread to the and 10bar) second ridge. After installing the parts, fix the parts for at least 30 minutes Loctite 5776 TEMPERATURE AND PRESSURE RELIEF VALVE Loctite remover Henkel Loctite 7200...

  • Page 102: Supplementary Information

    SUPPLEMENTARY INFORMATION Refrigerant collecting (pumpdown) for split model systems only Refer to “Refrigerant collection” in the outdoor unit installation manual or service manual. Back-up operation of boiler Heating operation is backed up by boiler. For more details, refer to the installation manual of PAC-TH011HT-E. <Installation & System set up> 1. Set DIP-SW 1-1 to ON "With boiler" and SW2-6 to ON “With Mixing tank”. 2. Install the thermistors THWB1 (Flow temp.) and THWB2 (Return temp.) *1 on the boiler circuit. 3. Connect the output wire (OUT10: Boiler operation) to the input (room thermostat input) on the boiler. *2 4. Install one of the following room temperature thermostats. *3 Wireless remote controller (option) Room temp.

  • Page 103: Service And Maintenance

    SERVICE AND MAINTENANCE Engineers Forms Should settings be changed from default, please enter and record new setting in ‘Field Setting’ column. This will ease resetting in the future should the system use change or the circuit board need to be replaced. Commissioning/Field settings record sheet Main remote controller screen Parameters Default setting Field setting Notes Main Zone1 heating room temp. 10–30°C 20°C Zone2 heating room temp. * 10–30°C 20°C Zone1 heating flow temp. 25–60°C 45°C Zone2 heating flow temp. * 25–60°C 35°C Zone1 cooling flow temp. 5–25°C 15°C 20°C Zone2 cooling flow temp. 5–25°C Zone1 heating compensation curve −9–+9°C 0°C...
  • Page 104 (From the previous page.) Engineers Forms Commissioning/Field settings record sheet (continued from the previous page) Default Field Main remote controller screen Parameters Notes setting setting Service menu Pump speed Pump speed (1–5) Heat source setting Standard/Heater/Boiler/Hybrid * Standard Operation Heating operation* Flow temp.range* Min.temp. (25–45°C) 30°C settings Max.temp. (35–60°C) 50°C Room temp.control * Mode (Normal/Fast)
  • Page 105 Annual Maintenance Log Book Contractor name Engineer name Site name Site number Cylinder unit maintenance record sheet Warranty number Model number Serial number Mechanical Frequency Notes Turn OFF water supply, drain DHW tank, remove mesh from strainer clean and replace in strainer. *1 Keep water supply OFF, open hot water taps and check the primary-side expansion vessel charge pressure. Top up if necessary (1 bar). Keep water supply OFF and check the potable vessel charge pressure. Top up if necessary (3.5 bar). Keep water supply OFF. In hard water areas de-scaling of the immersion heaters may be required.
  • Page 106 HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN Copyright 2014 MITSUBISHI ELECTRIC CORPORATION Issued: Sep. 2016 No.OCH570 REVISED EDITION-C Issued: Aug. 2015 No. OCH570 REVISED EDITION-B Issued: Apr. 2015 No. OCH570 REVISED EDITION-A Published: Dec. 2014 No. OCH570 Made in Japan Specifications are subject to change without notice.
  • Page 107 Related Links Model Number: EHPT20X-MHCW Ecodan Databook (M-P0744) Ecodan FTC5 - EHPT, EHST, EHPX, EHS(D)(C) Cylinder / Hydrobox Instruction Book (RG79D942H04) Ecodan FTC5 - EHPT20X-MHCW Monobloc Packaged Cylinder Product Information Sheet Ecodan FTC5 - EHPT20X-MHCW, EHST20(D)(C)-MHCW Cylinder Declaration of Conformity Ecodan FTC5 - EHPT20X-MHCW, EHST20(D)(C)-MHCW Cylinder Installation Manual (RG79D943H05)

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