A heat pump is an air conditioner that can run in reverse. In summer it moves heat out of the house, and in winter it pulls heat from the outdoor air and brings it inside. Because it does both jobs, a heat pump runs much of the year in Central Texas, and the problems that show up are a mix of AC issues and heating-specific ones. Requests sent through this site go to an independent contractor licensed by the Texas Department of Licensing and Regulation (TDLR).
Normal behavior that looks like a problem
- Steam from the outdoor unit in winter. That's usually the defrost cycle melting frost off the coil. The outdoor fan may stop for a few minutes while it runs. That's normal.
- Air that feels "lukewarm" from vents. Heat pump supply air is cooler than the air a gas furnace puts out, even when it's working correctly.
- "Aux" or "Emergency heat" on the thermostat. Auxiliary heat strips come on to help in cold weather or during defrost. Occasional use is normal. If aux heat runs constantly, something may be wrong, and your electric bill will show it.
Common heat pump problems
- Unit covered in ice that doesn't clear. Possible causes include a failed defrost control or sensor, low refrigerant, or a stuck outdoor fan.
- Blows cold in heat mode. Possible causes include a reversing valve or its solenoid, low charge, or a thermostat wired or set incorrectly.
- Won't cool in summer. The usual AC causes apply: capacitor or compressor, refrigerant leak, dirty coil or filter.
- High winter bills. This often comes from heavy reliance on backup heat strips.
- Short cycling or loud noises from the outdoor unit.
Safe homeowner checks
- Check the thermostat mode and setting, and replace its batteries if it uses them.
- Replace a dirty filter.
- Check the indoor breaker and the outdoor disconnect.
- Clear leaves, snow or ice buildup from around the unit, without chipping at the coil.
- If the unit is encased in ice, you can switch to Emergency Heat to stay warm and request service. Don't run it frozen for days.
Repair or replace?
Heat pumps run through both seasons, so they can wear sooner than a cooling-only AC. Age, the cost of the repair, the refrigerant type, and how often it has needed service all factor in. For a major failure on an older unit, see heat pump installation.
How a request works
Tell us what the system is doing, whether it's heating or cooling season, and any error codes. We'll forward your request to an independent licensed contractor serving your town, who will contact you to schedule a diagnosis.
Heat Pump Repair FAQs
Why is my heat pump steaming in winter?
That's usually the defrost cycle melting frost off the outdoor coil. Steam and a pause of the outdoor fan for a few minutes are normal.
Why does the air feel lukewarm?
Heat pump air is cooler than furnace air, even when it's working correctly. If the house can't hold its setting, request service.
My thermostat says AUX heat. Is that bad?
Occasional auxiliary heat during cold snaps or defrost is normal. If it runs all the time, the heat pump may not be doing its share, and bills climb.
Do heat pumps need more maintenance than an AC and furnace?
Not really. Change filters, keep the outdoor unit clear, and get yearly service. Because they run in both seasons, regular checkups help.
My heat pump is a block of ice. What do I do?
Switch to emergency heat if you need warmth, and request service. Don't chip at the coil.