TROUBLE SHOOTING
Problem
Insufficient refrigerant charge.
Unit operates
continuously but
Clogged filter dryer.
without performing
Reduced output from one or both circuits.
The overheating setting on the thermostatic
expansion valve is too low.
Frozen suction line
refrigerant charge too low.
Filters clogged.
Evaporator freezing
Insufficient charge.
Evaporator air intake temperature too low.
Vibrating pipe work.
Whistling noise from the thermostatic expansion
valve.
Excessive noise
Noisy compressor.
No pressure increase.
Presence of one or several oil or gas leaks in the
Low oil level in the
circuit.
compressor
Mechanical compressor damage.
Crankcase oil heater resistance fault.
No power at compressor.
High pressure pressostat activated.
Control circuit fuse blown.
Connection problem.
One or both
compressors do not
Electrical circuits thermal protection cuts in.
operate
Incorrect wiring.
Mains voltage too low.
Compressor motor short–circuited.
Compressor seized
Presence of a leak.
Low pressure
Insufficient refrigerant fluid charge.
pressostat being
activated.
Low air volume on evaporator.
Incorrect operation of the high pressure pressostat. Check the operation of the pressostat. Replace it if required.
High pressure
Outlet valve partially closed.
pressostat being
Non-condensable particles in the circuit.
activated
Condenser fan(s) not operating.
Insufficient refrigerant charge.
Liquid line too hot
Clogged filter dryer.
Liquid line frozen
Probable cause
25
Solution
Top up the refrigerant fluid charge.
Replace the filter.
Check the 4-ways valves and change them if necessary.
Increase the setting.
Check the refrigerant fluid charge.
Replace filters.
Check the refrigerant fluid charge.
Check the economiser setting.
Attach the pipe work correctly.
Check the pipe work attachments.
Add the refrigerant charge.
Check and replace the filter dryer if necessary.
Check the pressure difference of the 4-ways valves.
Seized bearings. Replace the compressor.
Check the tightness of the compressor attachment nuts.
Locate and repair the leaks and add oil.
Contact an approved Service Centre.
Check the electrical circuit and the condition of the
resistance. Replace defective parts if necessary.
Check the electrical circuit and seek out any grounding
and/or short-circuits. Check the fuses.
Reset the pressostat from the control panel and restart the
unit. Check for dirty condenser coil or defective fan.
Check the control circuit and look for any grounding and/or
short-circuits. Replace the fuses.
Check the tightness of all the electrical connection
terminals.
Check the operation of the control and safety devices.
Check amperage of compressor and discharge pressure
Check the wiring of the control and safety devices.
Check the power line.If the problem is due to the network,
inform the Electricity Company.
Check the continuity of the motor winding.
Replace the compressor.
Identify and repair the leak.
Add refrigerant charge.
check the blower and duct.
Open the valve. Replace it if required.
Bleed the circuit.
Check the wiring and the motors. Repair and replace if
required.
Locate and eliminate the causes of charge losses and top
up the refrigerant fluid charge.
Replace the filter cartridge.