Specifications

Troubleshooting | 23SM AH Series Heat
873392084 (2013/11)Revised 11-13
INSUFFICIENT
COOLING OR
HEATING
Unit undersized Recalculate heating and or cooling loads. If excessive, possibly adding
insulation and shading will rectify the problem
Loss of
conditioned air by
leakage
Check for leaks in duct work or introduction of ambient air through
doors or windows
Airflow Lack of adequate air flow or improper distribution of air. Replace dirty
filter
Refrigerant
charge
Low on refrigerant charge causing inefficient operation
Compressor Check for defective compressor. If discharge is too low and suction
pressure is too high, compressor is not pumping properly. Replace
compressor.
Reversing Valve Defective reversing valve creating bypass of refrigerant from discharge
of suction side of compressor. Replace reversing valve
Operating
pressures
Compare unit operation pressures to the pressure/temperature chart
for the unit.
TXV Check TXV for possible restriction or defect. Replace if necessary.
Moisture,
noncondensables
The refrigerant system may be contaminated with moisture or
noncondensables. Reclaim refrigerant, replace filter dryer, evacuate the
refrigerant system, and recharge with factory recommended charge.
BLOWER
OPERATES
BUT
COMPRESSOR
DOES NOT
Thermostat Check setting, calibration, and wiring.
Wiring Check for loose or broken wires at compressor, capacitor, or contactor.
Safety Controls Check UPM board red default L.E.D. for Blink Code
Compressor
overload open
If the compressor is cool and the overload will not reset, replace
compressor.
Compressor
motor grounded
Internal winding grounded to the compressor shell. Replace
compressor. If compressor burnout, install suction filter dryer.
Compressor
windings open
After compressor has cooled, check continuity of the compressor
windings. If the windings are open, replace the compressor.
Unit Troubleshooting
Problem Possible Cause Checks and Correction