Heat pump repair in Spokane, both modes working.

A heat pump is an air conditioner that can run backwards, which is why it can heat and cool from one machine — and why it has a few failure modes no other system has.

It only does one of the two jobs. Cooling fine but not heating, or the reverse, points squarely at the reversing valve or the solenoid that shifts it. That valve is the part that flips the system between modes, and when it sticks you lose exactly one direction while everything else keeps working normally. It is a distinctive symptom and a genuine diagnosis rather than a guess. If your unit is heating fine but has stopped cooling, the fault is usually on the AC-only side of the system — capacitor, contactor, or a low refrigerant charge — and the checks and typical repair prices on our Spokane AC repair page apply to a heat pump in cooling mode exactly the same way.

The outdoor unit is covered in ice. Some frost in cold weather is completely normal — the unit periodically runs a defrost cycle to clear it, and briefly blowing cool air indoors during that cycle is by design, not a fault. What is not normal is ice that never clears, or a solid casing of it. That means the defrost control, its sensor, or the reversing valve is not doing its job, and running the system that way risks damage. Never chip ice off with anything sharp; the coil fins and refrigerant lines behind them puncture easily.

Your electricity bill jumped without the weather changing. This is the quiet, expensive one. Nearly every heat pump has backup electric heat for the coldest days. If the heat pump itself is underperforming — low charge, a defrost fault, a failing outdoor fan — that backup takes over and holds the house at temperature, so nothing feels obviously broken. The only visible symptom is the bill, because resistance heat costs far more to run than the heat pump it replaced. If your thermostat shows auxiliary or emergency heat running in mild weather, something is wrong.

It struggles specifically on the coldest nights. Heat pumps lose output as the outdoor temperature drops, which is normal physics rather than a defect. It becomes a real problem when the unit was sized against milder assumptions than the site actually sees — a live issue north of Spokane, where Deer Park runs several degrees colder overnight than the city does. The fix there is correctly sized backup heat, not a bigger heat pump.

Because a heat pump works year-round instead of sitting idle for half the year, small faults compound faster than they would on a furnace-and-AC pair. A system that is limping rarely announces it — it just quietly runs on backup heat and bills you for the difference.

On a genuine no-heat night when the outdoor unit stops responding entirely, our 24/7 emergency HVAC dispatch covers exactly that — round-the-clock response for cold-snap failures. And because heat-pump economics shift sharply with the local electric rate and cold-night sizing, our Spokane County service areas page notes which nearby towns actually favor a heat pump over a straight furnace-and-AC pair.