Heat pump heating problem: sort the symptom before you troubleshoot
"Heating problem" is four different faults wearing one name. Telling them apart takes two minutes and saves a wasted service call.
A heating problem on a heat pump is rarely one problem. The house is cold, but the cause depends on what the system is actually doing. Start by naming the symptom, because each one has its own short list of checks.
Pick the one that matches yours.
Nothing runs at all
No fan, no sound, no warm air. That is a power or thermostat problem, or a safety lockout. Confirm the thermostat is set to heat above room temperature, check the indoor breaker and the outdoor disconnect, and give the unit five minutes after any outage. Our guide to a heat pump that will not turn on walks through that order.
It runs, but the air is cool
This is the most common complaint, and often it is not a fault. Heat pump air is warmer than your room but cooler than the blast from a furnace, so it can feel cold on your skin. Hold a thermometer at the vent. If the air is clearly colder than the room, it is a real problem. Read why a heat pump blows cold air for the checks.
It heats, but never catches up
The house stays a few degrees short on cold days. Look at the basics first: a clogged filter, closed vents, and an outdoor unit buried in snow or leaves. A heat pump also loses output as outdoor temperatures fall. So a system that is too small for the house will struggle in a deep freeze even when nothing is broken.
It heats some rooms and not others
That points at airflow, not the heat pump itself. Ducts, dampers and blocked returns decide where the warm air goes. See uneven heating in the house before you blame the equipment.
Check the mode and the settings
Heat pumps have more settings than a furnace. Confirm the thermostat is on heat, not cool or auto set wrong, and that the fan is on auto. A fan left on "on" pushes unheated air through the ducts between cycles, and that feels like a cold breeze.
What not to do
- Do not open the outdoor unit or touch the electrical parts inside. Some components can hold a dangerous charge even when the unit is off.
- Do not try to add or test refrigerant. Federal law requires EPA Section 608 certification, and handling it without one is illegal.
- Do not keep resetting a breaker that trips again.
When to call a licensed HVAC technician
Call one if the outdoor unit never starts, the air at the vent is colder than the room, or ice builds and does not clear. If you smell gas or a carbon monoxide alarm sounds, leave the house and call the gas company or 911 first.
Frequently asked questions
Why is my heat pump running but the house is still cold?
Common causes are a clogged filter, closed or blocked vents, an outdoor unit covered in snow or debris, or a system that is undersized for very cold weather. Check these before you call a technician.
Is cool air from a heat pump normal?
Often yes. Heat pump air is warmer than the room but cooler than furnace air, so it can feel cold. If a thermometer at the vent reads colder than the room, treat it as a fault.
Can I fix a heat pump heating problem myself?
You can check the thermostat, filter, vents and breaker, and clear debris outside. Anything inside the unit is electrical or refrigerant work for a licensed technician.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- ENERGY STAR. Air-Source Heat Pumps
- ENERGY STAR. Energy Savings at Home: Heating & Cooling