6.2 Troubleshooting
Before performing any troubleshooting steps on electrical components,
check the appliance’s operating status from the control panel screen.
Failure codes
Device failures are displayed in the control panel’s
Alarms
view.
Failure
Probable cause
Recommended actions
Refrigerant gas
detected
Gas leak indicator has detected gas. The unit
leaks refrigerant or there is external gas in the
machinery space (for example due to painting
work).
Try resetting the alarm. If the alarm
resets and the heat pump starts
again, there is no leak. If the alarm
persists and there is no outside
cause, contact Customer Service.
No cold water flow
Problem with pump, a closed valve, air in
pipes, lack of water, flow switch adjusted
incorrectly.
Check.
Electrical supply
phase fault
Wrong phase order in electricity supply, wire
loose, or blown fuse.
Check fuses. If ok, contact
Customer Service.
Suction pressure low Cooling water too cold or too low flow causing
ice in evaporator, problem with expansion
valve, or some refrigerant has leaked out.
Check operating conditions. If
not near freezing point, contact
Customer Service.
evaporator
temperature low
Cooling water too cold or too low flow causing
ice in evaporator, problem with expansion
valve, or some refrigerant has leaked out.
If enough refrigerant, evaporating and
condensing temperatures should be within 10
°C of water temperatures 10 min. after stop.
Check operating conditions. If
not near freezing point, contact
Customer Service.
Discharge pressure
high
Heating water too hot or too low flow in
condenser, or too high refrigerant charge
level. If refrigerant charge is correct,
condensing temperature should be within 5
°C of temperature of water out when running
(unless very low or very high flow).
Check warm water flow, check
warm water temperature
(compared to maximum).
Condensing
temperature high
Heating water too hot or too low flow in
condenser, or too high refrigerant charge
level. If refrigerant charge is correct,
condensing temperature should be within 5
°C of temperature of water out when running
(unless very low or very high flow).
Check warm water flow, check
warm water temperature
(compared to maximum).
Hot gas temperature
high
Compressor overheated, too high difference
between evaporating and condensing
temperature and too low power in
compressor.
If the compressor’s minimum power
is set lower than 60%, try raising
it, otherwise contact Customer
Service.
Suction superheat low Expansion valve control problem.
Contact Customer Service.
Motor starter tripped Too high current.
If VFD, check VFD for alarms,
otherwise check motor overcurrent
protection device in electrical
cabinet.
Communication lost to
VFD
Fieldbus communication problem between
controller and VFD.
Check wiring, contact Customer
Service.
Discharge pressure
high, pressure switch
Heating water too hot or too low flow in
condenser.
Check warm water flow, check
warm water temperature compared
to maximum.
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EXES01 2150EN
