HTW A60CGN8PLUS Manuel De L'utilisateur page 141

Symptom 3: Pump is making noise (cavitation)
POSSIBLE CAUSES
There is air in the system.
Water pressure at pump
inlet is too low.
Symptom 4: The water pressure relief valve opens
POSSIBLE CAUSES
The expansion vessel is broken.
The filling water pressure
in the installation is
higher than 0.3MPa.
Symptom 5: The water pressure relief valve leaks
POSSIBLE CAUSES
Dirt is blocking the water
pressure relief valve
outlet.
Symptom 6: Space heating capacity shortage at low outdoor temperatures
POSSIBLE CAUSES
Backup heater operation
is not activated.
Too much heat pump
capacity is used for
heating domestic hot
water (applies only to
installations with a
domestic hot water tank).
Symptom 7: Heat mode can't change to DHW mode immediately
POSSIBLE CAUSES
Volume of tank is too
small and the location of
water temperature probe
not high enough
CORRECTIVE ACTION
Purge air.
• Check on the manometer that there is sufficient water pressure.
The water pressure must be > 1 bar (water is cold).
• Check that the manometer is not broken.
• Check that the expansion vessel is not broken.
• Check that the setting of the pre- pressure of the expansion
vessel is correct (refer to "8.5.2 Water volume and sizing expansion
vessels").
CORRECTIVE ACTION
Replace the expansion vessel.
Make sure that the filling water pressure in the installation is about
0.10~0.20MPa (refer to "8.5.2 Water volume and sizing expansion
vessels").
CORRECTIVE ACTION
Check for correct operation of the pressure relief valve by turning the red
knob on the valve counter clockwise:
• If you do not hear a clacking sound, contact your local dealer.
• In case the water keeps running out of the unit, close both the
water inlet and outlet shut-off valves first and then contact your
local dealer.
CORRECTIVE ACTION
Check that the "OTHER HEATING SOURCE/ BACKUP HEATER"is
enabled, see "9.6 Field settings" Check whether or not the thermal protector
of the backup heater 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.
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 activate the booster heater for domestic water heating.
CORRECTIVE ACTION
• Set "dT1S5" to maximum value, and set "t_DHWHP_RESTRICT" to
minimum value.
• Set dT1SH to 2°C.
• Enable TBH, and TBH should be controled by the outdoor unit.
• If AHS is available, turn on first, if requirement for
turn heat pump on is fullfilled, the heat pump will turn on.
• If both TBH and AHS are not available, try to change the postion
of T5 probe(refer to 5 "General introduction").
60