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FAULT
POSSIBLE CAUSE
Indoor Fan not
Motor fault
running
No display on
Power supply
controller
Power to
Is unit in defrost mode?
controller but no
cooling from unit
Is unit in cooling mode
(cooling LED displayed)
Reduced airflow
Fan motor
Air inlets blocked
Evaporator coil dirty
Evaporator coil iced up
SYSTEM
Insufficient
Lack of refrigerant
cooling
Condenser coil dirty
Lack of ventilation to unit
Evaporator coil dirty
System settings
Service valves not open
correctly
Restriction in
piping/component
Head pressure
Condenser coil dirty
too high
System overcharged with
refrigerant
Condenser fan not
running
Lack of ventilation to unit
System load too high
(overstocked, door open
on coldroom)
Issue: 01.06.2023
CHECK
Is rocker switch on unit switched
on?
Is there correct voltage at
motor terminals?
Check fan capacitor
Is power switched on?
Is rocker switch on unit switched
on?
Is there correct voltage at
controller
Check if defrost LED is
displayed
Is room at required
temperature?
Room above required
temperature?
Is fan rotating slowly?
Is anything blocking air inlet
grilles at side of unit
Check condition of coil
Switch off unit and allow to
defrost
Is sight glass flashing
continuously?
Visual check of coil condition
Any obstructions around unit?
Visual check of coil condition
Controls (inc thermostat) set
correctly?
T.E.V. Superheat
Are valves fully open?
Is the filter drier blocked?
Sweating/frosting on outlet of
drier indicates a blockage
Damage to piping
Visual check of coil condition
Is head pressure high but liquid
line cool to touch?
See above (fan will not run)
Any obstructions around unit?
SOLUTION
If not - switch on
If yes - motor faulty. Replace motor
If no - check supply / wiring connections
Replace as required
If not - switch on
If not - switch on
If yes - controller faulty. Replace
controller
If no - check supply / wiring connections
If yes - all OK. Wait for defrost to end
If no - further checks required
All OK
Further checks required
Further checks required on fan (see
above)
Clear items from around unit
Clean as necessary
Checks required to determine cause of
icing
Leak test system and top up with
refrigerant
Clean condenser coil
Clear same to ensure good ventilation
Clean evaporator coil
Adjust as necessary
Adjust as necessary
Adjust as necessary
Replace filter drier
Replace piping as required
Clean condenser coil
Reclaim refrigerant/recharge correctly
See above
Clear same to ensure good ventilation
Reduce loading
Page 15
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