heat pump troubleshooting
Outdoor unit is not running
What it probably is, what you can safely check yourself, and the point where it becomes our job.
It is still running, so you have a few days. It is not going to fix itself, and the part that failed rarely fails alone.
What is most likely going on
If the indoor blower runs but the outdoor unit sits silent, you are almost always looking at power to the outdoor unit, a normal startup delay, or a failed capacitor or contactor. Two of those you can rule out yourself in five minutes.
Likely causes, most common first
- 1
Open disconnect or tripped outdoor breaker
The outdoor unit has its own circuit and a disconnect box within sight of the equipment. Landscapers, painters, roofers and previous service visits all leave that pull in the open position sometimes. It costs nothing to look, and it is the first thing we check when we arrive.
- 2
Anti-short-cycle or defrost delay
Controls hold the compressor off for several minutes after a power interruption or a normal cycle end. With Whatcom windstorms causing brief flickers most winters, a unit that is quiet for a few minutes is behaving correctly. Give it ten minutes before concluding anything.
- 3
Failed run capacitor
A dead capacitor is the classic no-start: you hear a hum or a click, the fan does not spin or spins reluctantly if you look at it, and nothing else happens. It is an inexpensive part and a fast repair, but the terminals hold a charge and it is not a homeowner job.
- 4
Burned or stuck contactor
The contactor is the relay that feeds power to the compressor and fan. Pitted contacts stop passing power, and a welded contactor does the opposite by never letting the unit shut off. Either way the fix is a part swap performed with the circuit de-energised.
- 5
Control signal never reaching the outdoor unit
A dead thermostat, a broken low-voltage wire under the house, or a control board fault means the outdoor unit is never being asked to run. In older Bellingham houses where the control wiring was retrofitted through a damp crawlspace, a chafed conductor is a real possibility.
What you can safely check yourself
Work down the list before you book anything. Plenty of calls end here, and we would rather you keep the money.
- Check the breaker for the outdoor unit and reset a tripped breaker exactly once.
- Confirm the disconnect pull or switch beside the outdoor unit is in the on position.
- Wait a full ten minutes with the thermostat calling for heat before deciding nothing is happening.
- Clear leaves, branches and snow from around and on top of the outdoor unit.
- Confirm the thermostat is not in emergency heat, which intentionally leaves the compressor off.
What is deliberately not on that list
Nothing above involves refrigerant, gas piping, or opening a live electrical panel. Refrigerant work is federally regulated and needs recovery equipment. Gas work done wrong kills people. An energised panel turns a $300 repair into a hospital visit. Electrical work on the circuit itself is done by a licensed electrical contractor. If a step you have read elsewhere involves any of those three, stop and call instead.
When to call us
Call us if the breaker trips again, if you hear a hum or repeated clicking with no fan movement, or if the unit stays silent after ten minutes with the thermostat calling. Capacitor and contactor work happens inside an energised panel and is not a do-it-yourself repair. Reach us at (360) 592-3824.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7
Tell us what it is doing
Describe the symptom and we will tell you what it takes to fix, what it is likely to cost, and whether it is worth fixing at all.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7