Frozen Heat Pump
Some frost on a heat pump is normal; solid ice isn't. Causes of a frozen heat pump, safe steps and when to call for repair.
Heat Pump Repair services
Each guide below covers one specific winter problem: symptoms, causes, what you can safely check and what a licensed technician does. Prices are explained in the heat pump repair cost guide.
Heat Pump Blowing Cold Air
Is your heat pump really blowing cold air, or just cooler air than a furnace? How to tell, plus causes like defrost, reversing valve and refrigerant.
Aux & Emergency Heat Problems
What AUX and EM heat mean on a heat pump thermostat, why your system may be stuck on backup heat, and how it affects your winter electric bill.
Ductless Mini-Split Repair
Mini-split blinking, not heating, leaking water or iced outdoors? Common ductless heat pump problems in winter and how they're repaired.
Heat Pump Running Constantly
When a heat pump running nonstop is normal, when it isn't, and the faults behind long run times: refrigerant, sizing, ducts and settings.
Common winter problems and where to start
| Problem | What usually causes it |
|---|---|
| Covered in ice | Light frost is normal; a solid block is not. Frozen heat pump. |
| Air feels lukewarm or cool | Partly normal, partly a warning sign. Cold air guide. |
| Stuck on aux or emergency heat | High bills and a silent outdoor unit. Aux heat explained. |
| Mini-split blinking or weak | Filters, error codes or low refrigerant. Mini-split repair. |
| Runs nonstop | Sometimes normal in deep cold. Constant running. |
Watch: winter heating explained
Short, silent clips hosted on muse.ai that show what to look for. They play muted and loop.
Coverage map: all 50 states and DC
Pick your state for local winter conditions, common heating fuels and the cities we route calls from. Colors show how severe winters are, based on IECC climate zones.
- Severe cold (IECC 6–8)
- Cold (5)
- Mixed (4)
- Mild (1–3)
How it works
- Tell us your heat pump type: ducted, ductless, dual-fuel, plus what the outdoor unit is doing.
- We connect you with a licensed heat pump provider covering your ZIP code.
- The technician checks defrost controls, refrigerant performance, reversing valve and backup heat.
- You approve the repair price before work starts.
- The system is run through a heating cycle, and a defrost cycle where conditions allow.
Decision guide
| What you see | Normal? | What to do |
|---|---|---|
| Thin white frost on the coil | Yes | Nothing; defrost will clear it |
| Steam rising from the unit | Yes, during defrost | Nothing |
| Thick ice encasing the unit | No | Turn to EM heat and call (guide) |
| Warm, not hot, air from vents | Usually | Heat pumps deliver lower-temperature air than furnaces |
| AUX on constantly above 35°F | No | Call; heat pump may not be running |
Before you call
Have the equipment type, brand and any blinking error code ready, and note what you've already checked. If anyone at home smells gas or a CO alarm sounds, leave the house and call 911 or the gas utility first.
Thawpoint Heat Pump Repair is a referral service. Your call is connected to an independent, licensed provider who serves your ZIP code and quotes the job directly. How it works.
Heat Pump Repair questions, answered
Do heat pumps work in freezing weather?
Yes. Standard heat pumps work efficiently down to around freezing and keep producing heat below it with reduced capacity. Cold-climate models are rated to deliver substantial heat at 5°F and some well below 0°F.
Why is my heat pump covered in ice?
Light frost is normal and cleared by defrost cycles. Heavy ice usually means a defrost control or sensor fault, low refrigerant, a stuck outdoor fan, or water dripping onto the unit from a gutter.
What's the difference between AUX and EM heat?
AUX (auxiliary) heat turns on automatically to help the heat pump when it can't keep up or during defrost. EM (emergency) heat is a manual setting that shuts off the heat pump and uses only backup heat.
Why does my heat pump blow cooler air than a furnace?
Heat pumps typically deliver air around 85–100°F, while gas furnaces deliver 120°F or more. The air feels cooler on your hand but still heats the house, with longer run times.
Is it normal for a heat pump to run all the time in winter?
In very cold weather, long or continuous run times can be normal. Constant running in mild weather, or with the house still cold, points to a problem.
How do I protect my heat pump from snow?
Keep 18–24 inches clear around the unit, make sure it sits on a stand or pad above typical snow depth, and keep roof runoff from dripping onto it. Never chip ice with sharp tools.