Where to start: troubleshooting a heat pump
If your heat is not working, start by checking the thermostat. Is it
turned on and set to heat? Try setting the temperature 2 to 4 degrees
above room temp. (When troubleshooting heat pumps in cooling mode,
follow this same process but set the temperature below room temp
instead of above.) Switch the fan on.
If the fan doesn’t start, check the fuses and breakers.
Replace the fuse or flip the circuit breaker to the closed position
and determine the cause of the overload. You may have a bad
connection, a seized blower motor or a shorted controller board. If
you didn’t blow a fuse or trip the circuit breaker, old or worn-out
wiring on your heat pump may be the cause . Wiring or loose terminals
will need to repaired or tightened. It could also be defective
thermostat or a stuck fan relay.
If your fan is running, but you still feel cold air at the
normal setting, check to see if warm air is coming out of the vents
when the thermostat is set to emergency heat. Make sure the thermostat
is at least five degrees above room temp. If you feel warm air, then
the problem is with the outdoor unit. If you don’t feel warm air, you
may have a defective thermostat or air handler to blame.
Examining the outdoor unit
Once you’ve determined the problem is with the outdoor unit, return
the thermostat to normal from the emergency heat setting. Wait a few
minutes before investigating the outside unit. When you inspect your
unit, do you notice ice or frost building up on the outdoor coil? This
may indicate a defective defroster timer or control module, or the
unit could be low on refrigerant. If there is no frost check to make
sure the airflow isn’t blocked by debris – grass clippings, sticks,
leaves and weeds can all accumulate and prevent air from going in and
out. Also check to see if the outdoor fan is running. If not, there
may be a problem with wiring, the fan motor or compressor run capacitor.
Beyond troubleshooting: heat pumps that require additional service
If you are unable to diagnosis and fix the problem with your heat
pump, or if you have additional questions, contact your local Trane
Comfort Specialist. A certified technician will help you correct the
problem and keep your home at a comfortable temperature.