MAINTENANCE DIAGNOSTIC
e-BALTIC-IOM-2020.12-EN
80
REFRIGERATION
FAULT
POSSIBLE CAUSE AND SYMPTOMS
SOLUTION
HP FAULT
Incorrect airflow rates
Heat pump mode:
Check the filter before the indoor
coil measure and estimate the
airflow rate increase the speed
of the fan
Cooling mode:
Check the condenser fan
Moisture or contaminants in the system
Summer operation
Several hours after the unit has stopped,
check for the presence of non-condensable
substances
Moisture or contaminants in the system
Condenser coil is obstructed
If the circuit pressure is higher (<1bar) than
the saturated pressure corresponding to the
measured outdoor temperature, there is
possibility that some contaminants are
present in the system.
Reclaim the refrigerant, and vacuum the
circuit (For flammable refrigerant, please
follow the procedure described in the
manual) Recharge the unit
Check the condenser coil and clean is
necessary
Recycled Hot Air
Check clearance around the condenser
Strong variations of pressure (2
to 3 bars). Expansion valve
“hunting”
Incorrect adjustment of the expansion valve
Refer to the LP FAULT section
Low refrigerant charge
Repair the leak and fill with liquid
The pressure regulator is not sufficiently
supplied with liquid
Refer to the LP FAULT section
Increase subcooling
Very high discharge
temperature, High amps
measured at compressor
Very high superheat, very hot compressor
Reduce the superheat on the expansion
valve. Check the pressure drop on the
filter drier in the suction line
Four Way reversing valve possibly
blocked, abnormal noise from the
valve, low LP and increasing HP
Check the operation of the valve by going
through cycle inversions. Change if
necessary.
Refer to LP FAULT
