Noritz NR501-OD Service Manual
  1. Manuals
  2. Brands
  3. Noritz Manuals
  4. Water Heater
  5. NR501-OD
  6. Service manual

Noritz NR501-OD Service Manual

Hide thumbs Also See for NR501-OD:
Table of Contents

Advertisement

Quick Links

See also: Owner's Manual , Installation Manual
NR501-OD
NR662-OD
NRC661 (-DV, -OD)
NRC711 (-DV,-OD)
Service Manual
• R e f e r t o t h i s m a n u a l w h e n e v e r p e r f o r m i n g s e r v i c e o r
maintenance on this appliance.
• This manual will be used for service technician training seminars.
• The specifications and descriptions in this manual may be
changed without prior notice.
• For further assistance, contact Noritz Technical Support at
1-866-766-7489.
Do not short circuit any safety device on
this appliance
Important Safety Information .................................................................................................... 2
1. Specifications/Performance Table ....................................................................................... 3
2. Dimensions ......................................................................................................................... 9
3. Components ....................................................................................................................... 12
4. Operating Principle ............................................................................................................. 16
5. Operation Flow Chart .......................................................................................................... 19
6. Wiring Diagram ................................................................................................................... 25
7. Troubleshooting .................................................................................................................. 28
• Error Codes and Checkpoints ......................................................................................... 28
• Circuit board checkpoints ................................................................................................ 29
• Error Code Diagnostic Flow Charts .............................................................................. 31
• Displaying Maintenance Monitors ................................................................................... 59
• Maintenance Monitor List ................................................................................................ 60
• Circuit Board Replacement ............................................................................................. 61
• When Changing the Fan Motor ....................................................................................... 63
• Gas Line Requirements ................................................................................................... 64
• Manifold Gas Pressure Adjustment ................................................................................. 67
• Periodic lnspection ......................................................................................................... 68
• Periodic Maintenance ..................................................................................................... 69
• Water Treatment ............................................................................................................. 73
• Changing Default Temperature Setting ........................................................................... 75
• Preventing Freeze Damage .................................................................................................. 76
8.
Installation Check .............................................................................................................. 79
NORITZ America Corporation
Gas Water Heater
Contents
1
Rev: Dec, 2013
KS-11-0004

Advertisement

Table of Contents
loading

Related Manuals for Noritz NR501-OD

Summary of Contents for Noritz NR501-OD

  • Page 1 • This manual will be used for service technician training seminars. • The specifications and descriptions in this manual may be changed without prior notice. • For further assistance, contact Noritz Technical Support at 1-866-766-7489. Do not short circuit any safety device on...

  • Page 2: Important Safety Information

    Caution lifting belt whenever necessary. • Use only the appropriate tools and parts: Only use replacement parts manufactured by Noritz for this model as listed in the Warning Installation Manual Parts List for service on this unit. Use appropriate tools.

  • Page 3: Specifications/Performance Table

    1. Specifications/Performance Table Specifications NR501-OD Specification Item Model Name NR501-OD Outdoor Wall Mounted Type Installation Air Supply/Exhaust Power Vented Ignition Direct Ignition Operating Pressure 15-150 psi Minimum Flow Rate 0.5 GPM (2 L/min.) Dimensions (Height) x (Width) x (Depth) 20.5" (520mm) x 13.8"...
  • Page 4 NRC661(-DV/-OD) Item Specification Model Name NRC661-DV NRC661-OD Type Installation Indoor Wall Mounted Outdoor Wall Mounted Air Supply/Exhaust Power Vented Ignition Direct Ignition Operating Pressure 15-150 psi Minimum Flow Rate 0.5 GPM (2 L/min.) Dimensions (Height) x (Width) x (Depth) 23.6" (600mm) x 13.8" 20.5"...
  • Page 5 Performance NR501-OD Item Maximum Performance Minimum Performance 120,000 btuh 15,000 btuh Consumption 120,000 btuh 15,000 btuh Maximum Hot Water Capacity 45°F (25°C) Rise 4.2 GPM (16.0 L/min.) Capacity Range 0.5-5.0 GPM (2-19.0 L/min.) °F Mode: Temperature Settings 115-140 °F (6 Options) °C Mode:...
  • Page 6 Hot Water Supply Capability <NR501-OD> [Winter] Inlet water temp. 46 ℉ [Spring / Fall] Inlet water temp. 64 ℉ [Summer] Inlet water temp. 82 ℉ Flow Rate [GPM] Flow Rate [GPM] Flow Rate [GPM] <NR662-OD> [Spring / Fall] Inlet water temp. 64 ℉...
  • Page 7 Pressure Loss Characteristics <NR501-OD> Flow rate [GPM] <NR662-OD> Flow rate [GPM]...
  • Page 8 <NRC661-DV, NRC661-OD> Flow rate [GPM] <NRC711-DV, NRC711-OD> Flow rate [GPM]...

  • Page 9: Dimensions

    2. Dimensions <NR501-OD> < inch (mm) > 13.3" (338mm) HEIGHT OF EACH FITTING FROM BOTTOM OF CASE (NR501-OD) 4- φ0.5" (φ13mm) HOT WATER OUTLET 1.8" (45mm) 2-0.3"×0.5" (6.5×13mm) OBLONG HOLE COLD WATER INLET 1.9" (49mm) 4.7" (120mm) 0.4" (10mm) 6.7" (170mm) 13.8"...
  • Page 10 <NRC661-DV> < inch (mm) > 13.3" (338mm) HEIGHT OF EACH FITTING FROM BOTTOM OF CASE NRC661-DV 0.8" (20mm) 4-φ0.5" (φ13mm) CONDENSATE DRAIN 2-0.3"×0.5" (6.5×13mm) OBLONG HOLE 1.8" (45mm) 13.8" (350mm) HOT WATER OUTLET 4.7" (120mm) 0.4" (10mm) 6.7" (170mm) 13.1" (334mm) 2.3"...
  • Page 11 <NRC711-DV> < inch (mm) > 13.3" (338mm) HEIGHT OF EACH FITTING FROM BOTTOM OF CASE NRC711-DV 0.8" (20mm) CONDENSATE DRAIN 4-φ0.5" (φ13mm) 1.8" (45mm) HOT WATER OUTLET 2-0.3"×0.5" (6.5×13mm) OBLONG HOLE 13.8" (350mm) 2.3" (58mm) COLD WATER INLET 4.7" (120mm) 0.4"...

  • Page 12: Components

    3. Components <NR501-OD> Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water <NR662-OD> Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water...
  • Page 13 <NRC661-DV> Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water <NRC661-OD> Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water...
  • Page 14 <NRC711-DV> Manifold Pressure Tap Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water <NRC711-OD> Manifold Pressure Tap Thermistor-Cold Water Thermistor-Hot Water...

  • Page 15: Display Window

    Display Window The display window allows you to view the status of unit or error codes. (Display Window) (Ex.NRC661-DV) When the gas burner is on. When the gas burner is on, set temperature is displayed for one minute. When unit is initially plugged into power, set temperature is displayed for approx.

  • Page 16: Operating Principle

    4. Operating Principle <NRC661 (-DV, -OD), NRC711 (-DV, -OD)> Thermistor-Cold Water Gas Proportioning Valve Thermistor- Hot Water...
  • Page 17 <NR501-OD, NR662-OD> Thermistor-Cold Water Gas Proportioning Valve Thermistor- Hot Water...
  • Page 18 < How to Use > 1.Normal Operation (Hot Water Production) 1. Turn the unit on. - If an optional remote controller is not installed with the unit, the unit will be on as soon as electricity is connected to it. *When electrical power is connected to the unit, the Set Temperature is displayed for approx.

  • Page 19: Operation Flow Chart

    5. Operation Flow Chart <NR501-OD> Shutdown procedure Water heating Ignition operation...
  • Page 20 <NR662-OD> Shutdown procedure Water heating Ignition operation...
  • Page 21 Freeze Prevention Control <NR501-OD, NR662-OD> Freeze prevention heater Thermistor-Air normal 301,302 / 30 Thermistor-Air less than 37 ﾟF (3 ﾟC Heaters turn ON Thermistor-Air less than 28 ﾟF (-2 ﾟC Heaters turn ON Heaters turn ON Thermistor-Air Thermistor-Air more than 14 ﾟF (-10 more than 14 ﾟF (-10...
  • Page 22 <NRC661 (-DV, -OD)> A : Displayed on Display Window. A / B B : Displayed on Optional Remote Controller. Connect power Display Monitor 768 / 768 transmission abnormality Water Servo-Main moves to High Limit switch 20 / 20 initial position setting abnormality sensor detects <...
  • Page 23 <NRC711 (-DV, -OD)> Shutdown procedure Water heating Ignition operation Note 1) ＊ = 1. 2. 3. 4. 5, 6, 7, 8, 9 Note 2) ＊ = 1. 2. 3 Note 3) ＊ = 1. 2, 4 Note 4) ＊ = 1. 2. 3. 4. F # = 1.
  • Page 24 <NRC661 (-DV, -OD), NRC711 (-DV, -OD)> Freeze prevention control Freeze prevention heater Thermistor-Air less than 37 Thermistor-Air 301, 302 / 30 normal Thermistor-Air less than 28 351, 352 / 35 Heaters turn ON Heaters turn ON SV conversion Heaters turn ON Thermistor-Exhaust normal Has 50 min passed...

  • Page 25: Wiring Diagram

    6. Wiring Diagram <NR501-OD, NR662-OD> COLOR CODING WIRING DIAGRAM : White : Black : Brown : Yellow : Gray : Red : Violet : Blue Minimum Manifold Pressure Set Button Circuit Board Block Diagram NEUTRAL 10A(FUSE) FAN CONTROL OUTPUT VARISTOR...
  • Page 26 <NRC661 (-DV/-OD)> Minimum Manifold Pressure Set Button Circuit Board Block Diagram NEUTRAL 10A(FUSE) FAN CONTROL OUTPUT VARISTOR PULSE VARISTOR CONTROL FAN ROTATION CIRCUIT FREEZE PREVENTION RELAY 1 VARISTOR ARRESTER SPEED INPUT HEATER EARTH DC140V DC140V FAN CURRENT POWER COMBUSTION FAN VALUE INPUT CONTROLLER RELAY 2...
  • Page 27 <NRC711 (-DV, -OD)> COLOR CODING WIRING DIAGRAM : White : Black : Brown : Yellow : Gray : Red : Violet : Blue Minimum Manifold Pressure Set Button Circuit Board Block Diagram NEUTRAL 10A(FUSE) FAN CONTROL OUTPUT VARISTOR PULSE VARISTOR CONTROL FAN ROTATION CIRCUIT...

  • Page 28: Troubleshooting

    If the Heat Exchanger is not flushed, the unit will repeat the warning indication and then shut off.The unit is locked Unit shuts off) before long.The unit can temporarily operate by reconnecting electrical power until the Heat Exchanger is flushed. Please contact Noritz America for more information about flushing the Heat Exchanger. Note 2) Detect Scale Build-up in the Heat The unit is locked because of repeated Scale Build-up error code.

  • Page 29: Circuit Board Checkpoints

    <NR501-OD, NR662-OD> Circuit Board Checkpoints Circuit board Check points (Check the wiring diagram Ref. Part Normal value behind the front cover) CN & Pin CN & Pin Overheat Prevention CN10 BL - W CN10 2Ω or less Device (Thermal Fuse)
  • Page 30 <NRC661 (-DV, -OD), NRC711 (-DV,-OD)> Circuit Board Checkpoints Circuit board Check points (Check the wiring diagram Ref. Part Normal value behind the front cover) CN & Pin CN & Pin Overheat Prevention CN10 BL - W CN10 2Ω or less Device (Thermal Fuse) W - O DC 1 - 16 V...
  • Page 31 No Error Code Error Page The Set Temperature is not displayed on Display Window when electrical power is connected Operation indicator does not light when turned on The fan does not operate when hot water fixture is opened Outlet water temperature incorrect Error Code displayed Error Code Description...
  • Page 32 1. No Error Code 1-1. The set temperature is not displayed on Display Window when electrical power is connected. Operation indicator does not light when turned on. Check the power outlet voltage. (AC108 - 132V ) Abnormal (Activated) Che ck the acti vation of the indoor T urn the breaker on.
  • Page 33 1-2. The fan does not operate when the hot water fixture is opened. 1 Check the Display Window. Check whether the Water Flow Sensor is normal. When 1 minute passes after the water flow is detected, the outside edge of the three digit display will rotate in a circular pattern.
  • Page 34 Check whether the Thermistor - Cold Water is normal. Normal Abnormal Circuit Board Check that actual water temperature and maintenance monitor #30 match. Display Window When not using the maintenance monitor: Fuse Circuit Board Main Thermistor-Cold Water converted from the Circuit Board resistance between CN63 White 4 - Black 2...
  • Page 35 1-3. Outlet water temperature incorrect Only connect and disconnect the connector after the fan has stopped rotating and then disconnect the electrical power. (The Circuit Board and Fan Motor may be damaged otherwise.) Check whether 2 dots (r ay Window. In this case, the actual outlet water temperature is colder than the Set Temperature .
  • Page 36 Check whether the manifold gas pressure is normal. Normal Abnormal Check whether the manifold gas Po ssible Recheck after adjusting pressure can be adjusted. the manifold gas pressure. * The procedure of Manifold Gas Impossible Adjustment is described in page 24. Check the voltage of the Gas Abnormal Replace the Circuit Board set .
  • Page 37 2. Error Code Displayed Error Codes Description Display Remote Window Controller Only connect and disconnect the connector after the fan has <Condition of occurrence for error code 11> stopped rotating and then disconnect the electrical power. Display was not possible at the time of initial (The Circuit Board and Fan Motor may be damaged otherwise.) ignition due to the causes listed below.
  • Page 38 Abnormal Check the voltage to the Primary Gas Solenoid Valve (SV0) Replace the Circuit Board set. and the Gas Solenoid Va lve-1 (SV1). * It is not necessary to replace the Normal Display Window Circuit Board. SV0 CN10 : Between White 10 - Blue 11 DC1 - 16V SV1 CN10 : Between Black 8 - Blue 11...
  • Page 39 Check that combustion conditions are normal. Primary gas pressure list Gas group Normal Abnormal Pressure Maximu m Abnormal Chec k whether the primar y gas pressure inch H 14.0 10.5 pressure Check the gas supply valve, etc. (dynamic pressure) is normal. Standard inch H 11.0...
  • Page 40 Error Codes Display Remote Description Window Controller 121, 122 The trouble diagnosis for “Error Code 12” is same as “Error Code 11”. <The occurrence condition for Error Code 121 and 122> Description Error Codes When the Unit fails the re-iginition after the Unit detected extinction. When the Unit detects extinction 6 times in 5 minutes.
  • Page 41 Error Codes Description Display Remote Window Controller Abnormally high output temperature 161, 162, 163 Check the Thermistor - Hot Water resistance. Normal Abnormal Circuit Board CN63 : Between White 1 - Black 2 Refer to the thermistor temperature Displ ay Window Fuse characteristics belo w.
  • Page 42 Error Codes Description Display Remote Window Controller Condensate Container clogging <Condition of occurrence for error code 29> Check the drain line is clogged or frozen. The error message is displayed if water level electrode is shorted. Normal Abnormal Check for the clogging of the Condensate Container drain system.
  • Page 43 Error Codes Display Remote Description Window Controller 311 (Open) Thermistor - Cold Water abnormality 312 (Short) Chec k the Therm istor - Cold Water open or short circuit . Normal Abnormal Circuit Board CN63 : Between White 4 - Black 2 DC 1 - 4.5V Resistance : Refer to the table below.
  • Page 44 Error Codes Description Display Remote Window Controller 331 (Open) Thermistor - Heat Exchanger abnormality 332 (Short) Chec k the Ther mistor - Heat Exchanger open or short circuit. Normal Abnormal Circuit Board CN63 : Between White 3 - Black 2 DC 1 - 4.5V Displ ay Window Resistance : Refer to the table below.
  • Page 45 Error Codes Display Remote Description Window Controller Failure of Gas Solenoid Valve 51, 511 (or Gas Solenoid Valve drive circuit abnormality) Check whether each connector (for SV0~SV3) on <Condition of occurrence for error code 51> When the Unit is in following conditions, the error code is displayed. - if the Gas Solenoid Valve's conections are improper.
  • Page 46 Error Codes Display Remote Description Window Controller Fan Motor abnormality 611, 612, 614 Only connect and disconnect the connector after the fan has <Condition of occurrence for error code 61> stopped rotating and then disconnect the electrical power. o l l (The Circuit Board and Fan Motor may be damaged otherwise.) - If the fan speed is 200rpm more or less than the target speed during iginition or pre purge.
  • Page 47 Error Codes Description Display Remote Window Controller Circuit Board abnormality Disconnect the electrical power, then reconnect electrical power to the Unit to reset the system. If the Circuit Board abnormality is continuous, replace the Circuit Board set. * It is not necessary to replace the Display Window Circuit Board. Error Codes Display Remote...
  • Page 48 Error Codes Display Remote Description Window Controller Remote Controller transmission abnormality No Display Check the voltage of Remote Controller terminal on Circuit Board . Normal Abnormal CN89A-CN89B Circuit Board DC14-16V Remove the Remote Controller cord. Display Window Fuse Circuit Board Main Circuit Board...
  • Page 49 Error Codes Display Remote Description Window Controller 901, 902, 903 Combustion abnormality (Unit is locked) ow abnormality <Condition of occurrence for error code 90> Detected abnor ow when the unit will start. 1 Check air inlet for blockage or obstruction. If 1 to 5 check out okay, replace the Fan Motor.
  • Page 50 <Condition of occurrence for error code 902> 902 Combustion abnormality “Output/FF+FB No . 50%” (Maintenance #52 / Maintenance #51 50%) Only connect and disconnect the connector after the fan has stopped rotating and then disconnect the electrical power. (The Circuit Board and Fan Motor may be damaged otherwise.) Abnormal To correct the setting Check the Dip Switch settings.
  • Page 51 Check the actual output. Normal Abnormal Should be maintenance monitor #51 (FF + FB No.) x 50% < #52 (Output) data. Check whether the Thermistor-Cold Water and Thermistor-Hot Water are normal. Normal Abnormal Disconnect electrical power, (pass through the water to the Unit.) e, and then reconnect electrical power.
  • Page 52 903 Combustion abnormality <Condition of occurrence for error code 903> When the unit is operating, - Air inlet for blockage or obstruction. - Exhaust for blockage or obstruction. - Fan Motor is abnormal. 1 Check air inlet for blockage or obstruction. 2 Check exhaust for blockage or obstruction.
  • Page 53 Error Codes Display Remote Description Window Controller Combustion abnormality (Unit is locked) <Condition of occurrence for error code 99> When the Unit has begun to operate, - Air inlet for blockage or obstruction - Exhaust for blockage or obstruction. And the li fe of the unit is close. It is the life of the unit.
  • Page 54 How to reset the lock of the unit (for error code 908 and 99) 1. Disconect electrical power. 2. Wait 10 seconds and reconnect electrical power. 3. Press and hold both the Mode and Maximum Manifold Pressure Set Button simultaneously for more than 5 seconds. (This procedure has to be perfomed within 10 minutes after reconnecting the power.) Mode Button Maximum Manifold...
  • Page 55 Troubleshooting for abnormalities due to Scale Build-up There are three case of inquires about Scale Build-up from users and professional. Case 1. Water Leak from the unit Case 2. Hot water is not delivered (The user can not get hot water) Case 3.
  • Page 56 Basically, recommend an authorized Nortiz plumber. If the users would like ves, send the procedure*, or access http://support.noritz.com/ to download the procedure*. *This procedure is only for use by rvice professional or authorized Noritz Service Representative. Any unauthorized use of this procedure may result in voiding the warranty.
  • Page 57 Va lve Bu cke t Circulating Pump Flushing Solution Wa ter Wa ter Outlet Inlet Supply **** Isolation valves may be purchased as an accessory from an authorized Noritz wholesaler. They allow f Contact Noritz America for more information (866-766-7489).
  • Page 58 8. Open the gas supply valve and water outlet valve (V2). The water heater can not operate 9 Check for correct operation of the water heater. if the “blue connector” f connected. Please contact Noritz America if more information is needed fo (Phone # : 866-766-7489)

  • Page 59: Displaying Maintenance Monitors

    Displaying Maintenance Monitors Display Window Remote Controller Press and hold the Mode Button for more than 2 seconds. Press and hold both the up [▲] and down [▼] Setting This can be done regardless if the unit is burning or not. Buttons simultaneously for more than 2 seconds.

  • Page 60: Maintenance Monitor List

    Maintenance Monitor List Data Minimum Data (Display Reading X Multiplier) Item Value for Multiplier Unit Indication Gas quality judging result Total Plug-in Time Disp. Range [000] - [999] X 100 hour 100 hour Disp. Range [000] - [1310] *3, 4 Disp.

  • Page 61: Circuit Board Replacement

    Circuit Board Replacement Procedure When swapping in a new circuit board, the new circuit board needs to be programmed. Failure to successfully program the circuit board will result in a 73 error code. Typically this programming can be done with a data transfer from the old circuit board to the new circuit board. Even a damaged circuit board can usually transfer data properly.
  • Page 62 1.05 Short Length 3.55 1.20 3.60 1.20 Long Length Natural NRC711-OD 2.75 0.95 3.45 1.20 NR501-OD Natural 2.70 1.05 3.05 1.25 NR662-OD Natural Natural 2.80 1.25 2.85 1.30 5. Once complete, hold the UP and DOWN buttons together for five seconds until the remote controller starts beeping rapidly.

  • Page 63: When Changing The Fan Motor

    When changing the Fan Motor. When Fan Plate(B) is installed in the old Fan Motor, install Fan Plate (B) to the new Fan Motor as shown in figure to maintain the proper air volume. When you change the Fan Motor, please remove this plate from the old Fan Motor, and install in the new Fan Motor. After changing the Fan Motor, please follow the procedure "Circuit Board Settings ".
  • Page 64 The installer must be professionally trained to do such work and must always follow all local and national codes and regulations. Gas line sizing calculations must be performed for every installation. Please contact Noritz America at 866-766-7489 if you have any questions or concerns.
  • Page 65 flame loss or ignition failure, which can result in gas leakage into the home. Refer to the NFPA 54 for details. Please contact Noritz for details. For corrugated stainless steel tubing (CSST) capacity tables, please consult with the manufacturer.
  • Page 66 Gas is approximately equivalent to 1000 BTU. Sample Gas Line Instructions 1. Size each outlet branch starting from the furthest Noritz Condensing Tankless Gas Water Heater using the Btuh required and the length from the meter. Barbecue (120,000 Btuh) 2. Size each section of the main line using the length to...

  • Page 67: Manifold Gas Pressure Adjustment

    Manifold Pressure (inch H Supply Pressure -DV(-SV) Model only Gas type Model Name Cover off (inch H Dip Switch 7 Vent Length Max value Min value 2.70 1.05 NR501-OD 11.0 3.05 1.25 2.80 1.25 NR662-OD 2.85 1.30 11.0 Short Length 3.15 1.05 Long Length 3.20...

  • Page 68: Periodic Inspection

    Periodic Inspection CAUTION To prevent burns or scalding, turn off the power button or power supply and wait until the unit cools before performing maintenance. Be sure to do. Air supply vent [When supplying combustion air from the indoors] For smear or blockage Check For dust and soot in Check...

  • Page 69: Periodic Maintenance

    Periodic Maintenance Uni t Wipe the outside surface with a wet cloth, then dry the surface. Use a neutral detergent to clean any stains. If an external condensate neutralizer is installed, periodic replacement of the neutralizing agent will be required. Refer to the instructions supplied with the neutralizer for suggested replacement intervals.
  • Page 70 Heat Exchanger must be flushed. is set to "Flushing Mode". from an authorized Noritz wholesaler.
  • Page 71 located...
  • Page 72 Periodic Maintenance Water Drain Valve (with Water Filter) If the water drain valve (with water filter) is covered with debris, the hot water may not run smoothly, or the unit may put out cold water. Check and clean the filter as explained below. * To avoid burns, wait until the unit cools down before draining the water.

  • Page 73: Water Treatment

    = 1, 2, 3, 4, F # = 1, 2, 3, 4, 5, 6, 7, 8, 9, A, b, C, d, E, F Damage to the water heater as a result of the items below is not covered by the Noritz America Limited Warranty.

  • Page 74: Regular Maintenance

    Sulfate ion : 250 mg/L or less Residual chlorine : 4 mg/L or less * Maximum limit suggested by Noritz. Isolation Valves * Isolation valves may be purchased as an accessory from Noritz. They allow for full diagnostic testing and easy flushing of the system.
  • Page 75 135 F (57 C) 140 F (60 C) OFF= Check Check • Applicable Model Noritz Condensing Tankless Gas Water Heater * Remarks [125 °F / 55 °C] Celsius display mode RC-7651M Optional remote controller Fahrenheit display mode Install the optional remote controller according to the instructions in the Installation Guide.

  • Page 76: Preventing Damage From Freezing

    * The freeze prevention heaters will not prevent the plumbing external to the unit from freezing. Protect this plumbing with insulation, heat tape or electric heaters, solenoids, or pipe covers. If there remains a freezing risk, contact the nearest Noritz agent. Take the measures below for extremely cold temperatures*. <Only using the remote controller>...
  • Page 77 Preventing Damage from Freezing-2 If the water heater will not be used for a long period of time, drain the water. Drain the water as follows: CAUTION To avoid burns, wait until the unit cools down before draining the water. The appliance will remain hot after it is turned off.
  • Page 78 Turning the Unit Back On 1. Check that all drain plugs are inserted. 2. Check that all hot water fixtures are closed. 3. Follow the procedure “Initial operation”, steps 1 through 4 in the Owner's Guide. 4. Make sure that the area around the appliance is well ventilated; open a window or a door if necessary. Then, operate the unit and verify that condensate is coming out of the drain pipe.

This manual is also suitable for:

Nr662-odNrc711-odNrc661-dvNrc661-odNrc711-dv

Table of Contents