Table 23. Troubleshooting checklist
Problem
Heating Cooling
Cause
Correction
No response to any thermostat setting
X
X
Main power off
Check fuses
X
X
Defective control transformer
Replace
X
X
Broken or loose connection
Repair
X
X
Defective thermostat
Replace
X
X
Transformer
Reset Transformer
Unit short cycles
X
X
Thermostat or sensor improperly located
Relocate
Blower runs, but compressor does not
X
X
Defective compressor overload
Replace (if external)
X
X
Defective compressor contactor
Replace
X
X
Supply voltage too low
Correct
X
X
Defective compressor capacitor
Replace
X
X
Defective windings
Replace
X
X
Limit switches open
Check cause/Replace or repair
Insufficient capacity
X
X
Dirty filter
Replace/clean
X
X
Blower RPM too low
Correct
X
X
Loss of conditioned air due to leaks in ductwork
Repair leaks
X
Introduction of excessively hot return-air
Correct
X
Introduction of excessively cold return-air
Correct
X
X
Low on refrigerant charge
Locate leak, repair and recharge by weight
(not by superheat)
X
X
Restricted thermal expansion valve
Replace
X
X
Defective reversing valve
See WSHP-IOM-# for touch test chart
X
X
Thermostat improperly located
Relocate
X
X
Unit undersized
Recalculate heat gains/losses
X
X
Inadequate water flow
Increase GPM
X
X
Scaling in heat exchanger
Clean or replace
X
Water too hot
Decrease temperature
X
Water too cold
Increase temperature
High pressure switch open
X
Inadequate GPM
Increase water flow to unit
X
Water too hot
Decrease temperature
X
Inadequate airflow
Check, clean blower and coil
X
Dirty filter
Clean/replace
X
X
Overcharged with refrigerant
Decrease charge
X
X
Defective pressure switch
Check or replace
High head pressure
X
Trash in heat exchanger
Back flush
X
Low water flow
Increase GPM
X
X
Overcharge of refrigerant
Decrease charge
X
X
Non-condensable in system
Evacuate and recharge by weight
X
X
Water too hot
Decrease temperature
X
Dirty filter
Clean / replace
X
Inadequate airflow
Check, clean blower and coil
Low suction pressure
X
X
Undercharged
Locate leak, repair and recharge
X
X
Restricted thermal expansion valve
Repair / replace
X
Inadequate airflow
Check, clean blower and coil
X
Dirty filter
Clean/replace
X
Inadequate GPM
Increase GPM
Troubleshooting
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WSHP-SVX10H-EN