Troubleshooting

Checklist

Problem

Heating

Cooling

Cause

Correction

 

X

X

Main power off

Check fuses

No response to any

X

X

Defective control transformer

Replace

X

X

Broken or loose connection

Repair

thermostat setting

X

X

Defective thermostat

Replace

 

 

X

X

Transformer

Reset Transformer

Unit short cycles

X

X

Thermostat or sensor improperly located

Relocate

 

X

X

Defective compressor overload

Replace (if external)

 

X

X

Defective compressor contactor

Replace

Blower runs, but compressor does not

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

 

X

X

Dirty filter

Replace/clean

 

X

X

Blower RPM too low

Correct

 

X

X

Loss of conditioned air due to leaks in

Repair leaks

 

ductwork

 

 

 

 

 

 

 

 

 

 

 

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)

Insufficient capacity

 

 

 

 

 

 

 

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

 

 

X

Inadequate GPM

Increase water flow to unit

 

 

X

Water too hot

Decrease temperature

High pressure switch open

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

 

 

X

Trash in heat exchanger

Backflush

 

 

X

Low water flow

Increase GPM

High head pressure

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

 

X

X

Undercharged

Locate leak, repair and recharge

Low suction pressure

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

 

X

 

Inadequate GPM

Increase GPM

 

X

 

Water too cold

Increase temperature

Low Pressure switch open

 

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

34

WSHP-SVX04A-EN

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Trane WPHF, WPVJ manual Troubleshooting Checklist, Unit short cycles