Heat Pump Not Heating? Causes and Fixes
A heat pump that will not heat is usually dealing with a defrost issue, an electrical failure, a refrigerant problem or a control fault.
Common causes
Defrost cycle problems
Ice that does not clear from the outdoor unit reduces heating.
Reversing valve faults
If the valve is stuck, the system cannot switch properly between heating and cooling.
Refrigerant leak
Low charge reduces heating ability.
Outdoor fan or compressor issues
Failed components prevent the outdoor unit from working.
Thermostat or control issues
Wrong settings or communication faults can cause heating to fail.
Auxiliary heat problems
If backup heat fails, the home may not warm on the coldest nights.
What you can safely check
- Confirm the thermostat is set to Heat and above room temperature.
- Check the filter.
- Look at the outdoor unit for ice. A thin layer that clears is normal in defrost.
- Check the breaker.
When to call a professional. Call a technician if cold air continues, the outdoor unit does not run, ice does not clear, or emergency heat runs constantly. Never open electrical panels or remove access covers on equipment. If you smell burning or see smoke, turn off power and call 911 if there is any danger.
Why is my heat pump blowing cold air?
A brief cool blast during defrost is normal. Ongoing cold air points to a problem.
Why is emergency heat on?
Emergency heat means the system is using electric strips. Constant use can raise your bill and signals a heat pump problem.
Can I run the heat pump with ice on it?
A thin frost that clears during defrost is normal. Thick ice that stays needs service.
Comfortable again, without the runaround
$30 off your first service call. Mention this website when scheduling. Cannot be combined with other offers. Excludes diagnostic fee and maintenance visits.