Running Information; Thermistor Reading; Summary Of Settings; Error History - Mitsubishi Electric EHST20C-VM6HB Service Manual

Running information

This function shows current temperature and other data of main component parts
of both the indoor and outdoor units.
1. From the Service menu highlight Running information.
2. Press CONFIRM.
3. Press F3 and F4 buttons to set the Ref. address.
4. Use the function buttons to enter index code for the component to be viewed.
(See the Table 9-2-1 for component index codes.)
4. Press CONFIRM.

Thermistor reading

This function shows the current readings of thermistors located on the water and refrigerant circuit
Thermistor Description
TH1A Zone 1 room temperature
TH1B Zone  room temperature
Refrigerant return temperature
TH
Water flow temperature
THW1
THW Water return temperature
DHW tank water temperature
THW5
TH7 Ambient (outdoor) temperature

Summary of settings

This function shows the current installer/user entered settings.
Abbreviation Explanation
DHW max temp
HWtemp
HWdrop DHW temperature drop
DHW max operation time
HWtime
NO HW DHW mode restriction
HWset DHW operation mode (Normal/Eco)
Legionella hot water temp
Ltemp
Legionella operation Frequency
Lfreq
Legionella mode start time
Lstart
Legionella max. operation time
Ltime
Duration of max (Legionella) hot
Lkeep
water temp
Z1 mode Operation mode
- HER (Heating room temp)
- HE (Heating flow temp)
- HCC (Heating compensation curve)
- COR (—)
- CO (—)

Error history

Error history allows the service engineer to view previous Error codes, the unit
address and the date on which they occurred. Up to 16 Error codes can be stored
in the history the most recent Error event is displayed at the top of the list.
From the service menu select Error history
1.
Press CONFIRM.
.
Please see chapter 10-4. for error code diagnosis and actions.
To delete an Error history item;
From Error history screen press F4 button (Rubbish bin icon)
1.
Then press F3 button (Yes).
.
OCH531
Thermistor Description
Zone 1 flow water temperature
THW6
Zone 1 return water temperature
THW7
Zone 2 flow water temperature
THW8
Zone 2 return water temperature
THW9
Boiler flow water temperature
THWB1
Boiler return water temperature
THWB
Abbreviation Explanation
Z2 mode Operation mode
- HER (Heating room temp)
- HE (Heating flow temp)
- HCC (Heating compensation curve)
- COR (—)
- CO (—)
Heating target room temp
Hroom 1
Heating target room temp
Hroom 2
Heating target flow temp
Hflow 1
Heating target flow temp
Hflow 2
Croom —
Cflow —
Freeze stat function flow temp
FSflow
Freeze stat function ambient temp
FSout
4