ClimateMaster ACL2120CAZ, Installation Instructions Manual, Page: 43 / 52

43
Diagnostics
9.0 DIAGNOSTICS & TROUBLESHOOTING
SYMPTOM POSSIBLE CAUSE REMEDY
Moisture Poor evacuation on installation or during service
In each case, the cure is the same. Recover refrigerant.
Add filter drier, evacuate, and recharge.
High head pressure Noncondensibles air
Unusual head and
suction readings
Wrong refrigerant or mixed refrigerants
Foreign matter –
copper filings
Copper tubing cuttings
Copper oxide Dirty copper piping or nitrogen not used when
brazing
Welding scale Nitrogen not used during brazing
Soldering flux Adding flux before seating copper partway
Excess soft solder Wrong solder material
LOSS OF LUBRICATION
SYMPTOM POSSIBLE CAUSE REMEDY
Compressor failures Vapor line tubing too large Reduce pipe size to improve oil return.
Low suction pressure Low charge Check system charge.
Refrigerant leaks Repair and recharge.
Cold, noisy
compressor –
Slugging
Dilution of oil with refrigerant Observe piping guidelines.
Noisy compressor Refrigerant migration in off-cycle Check or add crankcase heater.
Cold, sweating
compressor
Flooding Check system charge.
Low load Reduced indoor airflow Dirty filter
Dirty indoor coil
Wrong duct size
Restricted duct
Thermostat setting Advise customer.
Short cycling of
compressor
Cycling or faulty high- or low-pressure control Check pressure and address cause of high or low
pressure. Replace pressure control if faulty.
Loose wiring Check all control wires.
Thermostat In supply air stream, out of calibration
Customer misuse
SLUGGING
SYMPTOM POSSIBLE CAUSE REMEDY
On start-up Incorrect piping Review pipe size guidelines.
TXV hunting when
running
Faulty indoor TXV Replace TXV.
CONTAMINATION
9.3 Service Analyzer Charts (cont.)