132
ENGLISH
Symptom 6: Space heating capacity shortage at low outdoor temperatures
POSSIBLE CAUSES
CORRECTIVE ACTION
Backup heater operation is not activated.
Check that the "OTHER HEATING SOURCE/ BACKUP HEATER"is enabled,
see "10.5
Field settings" Check whether or not the thermal protector of the backup he-
ater has been activated (refer to "Controls parts for backup heater(IBH)").
Check if booster heater is running, the backup heater and booster heater can’t
operate simultaneously.
Too much heat pump capacity is used for heating domestic hot
water (applies only to installations with a domestic hot water
tank).
Check that the "t_DHWHP_MAX" and "t_DHWHP_RESTRICT" are configured
appropriately:
• Make sure that the "DHW PRIORITY" in the user interface is disabled.
• Enable the "T4_TBH_ON" in the user interface/FOR SERVICEMAN to acti-
vate the booster heater for domestic water heating.
Symptom 6: Space heating capacity shortage at low outdoor temperatures
Symptom 7: Heat mode can’t change to DHW mode immediately
POSSIBLE CAUSES
CORRECTIVE ACTION
Volume of tank is too small and the location of water tempera-
ture probe not high enough
• Set "dT1S5" to maximum valve, and set "t_DHWHP_RESTRICT" to
minimum valve.
• Set dT1SH to 2°C.
• Enable TBH, and TBH should be controlled by the outdoor unit.
• If AHS is available, turn on first, if requirement for turn heat pump on is
fulllled, the heat pump will turn on.
• If both TBH and AHS are not available, try to change the postion of T5
probe(refer to 2 "General introduction").
Symptom 6: Space heating capacity shortage at low outdoor temperatures
Symptom 8: DHW mode can’t change to Heat mode immediately
POSSIBLE CAUSES
CORRECTIVE ACTION
Heat exchanger for space heating not big enough
• Set "t_DHWHP_MAX" to minimum valve, the suggested valve 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
Space heating load is small
Normal , no need for heating
Disinfect function is enabled but without TBH
• Disable disinfect function
• add TBH or AHS for DHW mode
Manual turn on the FAST WATER function, after the hot water meets
the requirements, the heat pump fails to switch to the air-conditio-
ning mode in time when the air conditioner is in demand
Manual turn off the FAST WATER function
When the ambient temperature is low, the hot water is not enough
and the AHS is not operated or operated late
• Set "T4DHWMIN", the suggested valve is ≥ -5
• Set "T4_TBH_ON", the suggested valve is ≥ 5
DHW mode priority
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.
Symptom 6: Space heating capacity shortage at low outdoor temperatures
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 control-
led by the unit.
Symptom 6: Space heating capacity shortage at low outdoor temperatures
Summary of Contents for 20191845
Page 72: ...74 ITALIANO ...
