Heat Pump Troubleshooting
Heat Pump Not Heating — What's Wrong & What to Do
A heat pump that runs without producing useful heat may have an airflow, control, defrost, refrigerant, capacity, or component problem. Some checks are safe for a homeowner; others require professional diagnosis.
What to Expect
Check your thermostat is in HEAT mode (not COOL or AUTO cooling)
Check outdoor unit for ice buildup — may need manual defrost
Low refrigerant is a common cause of poor heating
Failed reversing valve can prevent heat mode from engaging
Defrost board or sensor failure — common in Maine winters
Service scheduling depends on current demand, location, and required parts
Frequently Asked Questions
Why is my heat pump blowing cold air in heat mode?
Brief cooler airflow can occur during defrost, but persistent cold air may indicate a control setting, reversing-valve fault, low refrigerant, airflow restriction, or capacity issue. A technician should diagnose persistent symptoms.
My heat pump has ice on it and isn't heating. What do I do?
Light frost is normal and the unit will defrost automatically. Heavy ice that doesn't clear indicates a defrost board or sensor failure, or low refrigerant. Turn the system off and call us — continuing to run an iced unit can damage the compressor.
My heat pump is running but my house isn't warming up. Why?
At very low outdoor temperatures, heat pump output is reduced. If the outdoor temp is below -5°F, your backup heat should be engaged. If backup heat is also failing, there may be an electrical or control issue — call us for diagnosis.
How quickly can RG Mechanical respond to a heat pump heating failure?
Availability depends on weather, call volume, location, access, and parts. Call with the symptoms so current scheduling and safe interim steps can be discussed; no response time is guaranteed.
Ready to get started?
Call us or request a project estimate. Contact RG Mechanical to confirm service availability for your community.
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