Midea M-thermal Mono Series - Operation Parameter; DHW Mode Can’t Change to Heat Mode Immediately; DHW Mode Heat Pump Stop Work but Setpoint Not Reached

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Symptom 8: DHW mode can’t change to Heat mode immediately
POSSIBLE CAUSES CORRECTIVE ACTION
Heat exchanger for space
heating not big enough
Space heating load is small
When the ambient temperature is
low, the hot water is not enough
and the AHS is not operated or
operated late
DHW mode priority
Manual turn on the FAST WATER
function, after the hot water meets
the requirements, the heat pump
fails to switch to the air-conditioning
mode in time when the air
conditioner is in demand
Disinfect function is
enabled but without TBH
Normal , no need for heating
Manual turn off the FAST WATER function
If there is AHS or IBH connect to the unit, when the outdoor unit failed, the
hydraulic module board must run DHW mode till the water temperature
reach the setting temperature before change to heating mode.
• Disable disinfect function
• add TBH or AHS for DHW mode
• Set "T4DHWMIN", the suggested value is ≥ -5℃
• Set "T4_TBH_ON", the suggested value is ≥ 5℃
• Set "t_DHWHP_MAX" to minimum value, the suggested value is
60min.
• If circulating pump out of unit is not controlled by unit, try to
connect it to the unit.
• Add 3-way valve at the inlet of fan coil to ensure enough water
flow.
Symptom 9: DHW mode heat pump stop work but setpoint not reached, space heating require heat but unit stay in DHW mode
POSSIBLE CAUSES
CORRECTIVE ACTION
Surface of coil in the tank
not large enough
The same solution for Symptom 7
TBH or AHS not available
Heat pump will stay in DHW mode untill "t_DHWHP_MAX" reached or
setpoint is reached. Add TBH or AHS for DHW mode,TBH and AHS should
be controlled by the unit.
13.3 Operation parameter
This menu is for installer or service engineer reviewing the operation parameters.
At home page, go to ''MENU''>''OPERATION PARAMETER''.
Press ''OK''. There are six pages for the operating parameter as following. Press ''▼ ''、 ''▲'' to scroll.
OPERATION PARAMETER #01
OPERATE MODE COOL
ADDRESS
SV1 STATE ON
ONLINE UNITS NUMBER 1
SV2 STATE OFF
SV3 STATE OFF
PUMP_I ON
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OPERATION PARAMETER
#01
PUMP-C OFF
ADDRESS
PUMP-S OFF
PUMP-O OFF
PUMP-D OFF
PIPE BACKUP HEATER OFF
TANK BACKUP HEATER ON
2/9
OPERATION PARAMETER
#01
T1 LEAVING WATER TEMP. 35°C
ADDRESS
WATER FLOW 1.72m
3 /h
GAS BOILER OFF
HEAT PUMP CAPACTIY 11.52kW
POWER CONSUM. 1000kWh
Ta ROOM TEMP 25°C
3/9
OPERATION PARAMETER
#01
Tw2 CIRCUIT2 WATER TEMP. 35°C
ADDRESS
TIS’ C1 CLIMATE CURVE TEMP. 35°C
T5 WATER TANK TEMP. 53°C
TIS2’ C2 CLIMATE CURVE TEMP. 35°C
TW_O PLATE W-OUTLET TEMP. 35°C
TW_I PLATE W-OUTLET TEMP. 30°C
4/9
OPERATION PARAMETER
#01
Tbt2 BUFFERTANK_LOW TEMP. 35°C
ADDRESS
IDU SOFTWARE 01-09-2019V01
Tbt1 BUFFERTANK_UP TEMP. 35°C
5/9
Tsolar 25°C
OPERATION PARAMETER #01
COMP.CURRENT 12A
ADDRESS
COMP.FREQENCY 24Hz
ODU MODEL 6kW
COMP.RUN TIME 54 MIN
COMP.TOTAL RUN TIME 1000Hrs
EXPANSION VALVE 200P
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