34 WSHP-SVX04A-EN
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
XX
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 Replace
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 air flow 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 Backflush
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 air flow 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 air flow Check, clean blower and coil
X Dirty filter Clean/replace
X Inadequate GPM Increase GPM
Low Pressure switch open
X Inadequate GPM Increase GPM
X Water too cold Increase temperature
X Inadequate air flow Increase CFM
X Dirty filter Clean/replace
X X Undercharged with refrigerant Increase charge
X X Defective pressure switch Replace
X X Heat transfer fluid too cold Raise water temperature