Troubleshooting guide
Heat pump not cooling? Here is what is happening and what to do.
A heat pump that won't cool usually has one of three problems: dirty coils restricting heat exchange, a refrigerant leak, or an iced-over indoor coil from a clogged filter. Filter and outdoor coil cleanliness account for the majority of cases we see. Refrigerant leaks require professional diagnosis.
Likely causes, ranked by probability
- 1
Dirty outdoor coil
Restricts heat rejection. Most common cause we see in summer.
Likelihood 35%
- 2
Clogged filter and iced indoor coil
Restricted airflow causes the indoor coil to freeze.
Likelihood 30%
- 3
Low refrigerant
Slow leak reducing capacity.
Likelihood 20%
- 4
Failed capacitor on outdoor unit
Compressor or fan won't start.
Likelihood 15%
What you can try first
- · Wash the indoor filter
- · Rinse the outdoor coil with garden hose at low pressure
- · Turn the system off for an hour if the indoor coil is iced
When to call us: Outdoor coil is clean, filter is clean, and the system still won't cool.
When a cleaning helps, and when to call a repair pro
A good portion of “something is off” symptoms (musty smell, weak airflow, water dripping from the indoor unit, surface mold) trace back to a dirty blower wheel, clogged drain, or biofilm on the coil. A full disassembly cleaning solves those. If we get on site and find an electrical or mechanical fault (a failing capacitor, a stuck reversing valve, refrigerant issues), we will tell you and recommend a heat pump repair contractor. We do not do repairs ourselves.
Frequently asked questions
Is heat pump not cooling dangerous?
Most causes of "heat pump not cooling" are not immediately dangerous, but ignoring them can damage the system over time. Outdoor coil is clean, filter is clean, and the system still won't cool.
Can a cleaning fix this?
Sometimes. Biofilm, dirty coils, and clogged drain lines often resolve after a deep clean. Mechanical or electrical issues need a heat pump repair contractor instead.
Do you do repairs?
No. We focus on cleaning and twice-yearly maintenance. If your system needs a part replaced or an electrical fix, we will tell you what we see and recommend a repair contractor.
Try a cleaning first.
If the symptom traces back to a dirty unit, we can fix it. If it does not, we will tell you and point you to a repair pro.