General Troubleshooting Guide - Rheem A17 Series Installation Instructions Manual

10.0 DIAGNOSTICS AND TROUBLESHOOTING

10.6 General Troubleshooting Guide

WARNING:
Disconnect all power to unit
before servicing. Contactor may break only one side. Failure
to shut off power can cause electrical shock resulting in per-
sonal injury or death.
SYMPTOM
Unit will not run
Outdoor fan runs,
compressor doesn't
Insufficient cooling
Compressor short cycle
Registers sweat
High head, low suction
pressure
High head, high or normal
suction pressure - Cooling
mode
Low head, high suction
pressure
Low suction, cool com-
pressor, iced indoor coil
High suction pressure
Fluctuating head and
suction pressure
Gurgle or pulsing noise
at expansion device or
liquid line
42
POSSIBLE CAUSE
• Power off or loose electrical connection
• Thermostat out of calibration - set too high
• Defective control board
• Blown fuses/tripped breaker
• Transformer defective
• High-pressure control lock-out
• Low-pressure control lock-out
• Miswiring of communications (communication
light on continuously)
• Run or start capacitor defective
• Contactor defective
• Loose connection
• Compressor stuck, grounded or open motor
winding, open internal overload.
• Low-voltage condition
• Improperly sized unit
• Improper indoor airflow
• Incorrect refrigerant charge
• Air, noncondensibles, or moisture in system
• Bad ID EXV or TXV
• Incorrect voltage
• Defective overload protector
• Refrigerant undercharge or undercharge (HPC
or LPC cycling)
• Low indoor airflow
• Restriction in liquid line, expansion device, or
filter drier
• Bad EXV or TXV
• Dirty outdoor coil
• Refrigerant overcharge
• Outdoor fan not running
• Air or noncondensibles in system
• EXV in bypass mode or TXV Check valve
stuck open
• Bad compressor
• Low indoor airflow
• Operating below 65oF outdoors
• Moisture in system
• Restricted indoor coil circuit
• Excessive load
• Defective compressor
• EXV or TXV hunting
• Air or noncondensibles in system
• Air or noncondensibles in system
• Undercharged System
REMEDY
• Check for correct voltage at line voltage connections in con-
densing unit.
• Reset
• Check control board diagnostic codes
• Replace fuses/reset breaker
• Check wiring. Replace transformer
• Reset by cycling power to unit. Also see high head and low
suction pressure remedies.
• Check for refrigerant leaks.
• Check communication wiring.
• Replace
• Replace
• Check for the correct voltage at compressor. Check and tighten
all connections.
• Wait at least 3 hours for overload to reset. If still open, replace
the compressor.
• Add start kit components.
• Recalculate load
• Check. Should be approximately 400 CFM per ton
• Charge per procedure attached to unit service panel
• Recover refrigerant. Evacuate and recharge. Add filter drier
• Replace EXV or TXV
• At compressor terminals, voltage must be 10% of nameplate
marking when unit is operating.
• Replace. Check for correct voltage
• Add refrigerant
• Increase speed of blower or reduce restriction.
• Replace air filter.
• Remove or replace defective component.
• Verify thermistor and pressure transducer connection and
operation
• Replace EXV or TXV
• Clean coil
• Correct system charge
• Repair or replace
• Recover refrigerant. Evacuate and recharge
• Verify thermistor and pressure transducer connection and
operation
• Replace EXV or TXV
• Replace compressor
• Increase speed of blower or reduce restriction. Replace air filter
• Add Low Ambient Kit
• Recover refrigerant. Evacuate and recharge. Add filter drier
• Repair or replace indoor coil
• Recheck load calculation
• Replace
• Check thermistor to suction line connection
• Check air distribution on coil
• Check suction thermistor and pressure transducer and opera-
tion
• Recover refrigerant. Evacuate and recharge.
• Remove and confirm EXV movement. Clean EXV inside with
nitrogen to remove any debris then reinstall
• Recover refrigerant. Evacuate and recharge
• Adjust charge per charging chart