Troubleshooting guide
Heat pump blowing cold air in heat mode? Here is what is happening and what to do.
A heat pump blowing cold air in heat mode usually means the system is in defrost cycle (which is normal and self-resolves in 5-15 minutes), the reversing valve is stuck, or the system has lost refrigerant. If it persists for over an hour, turn off and call a pro.
Likely causes, ranked by probability
- 1
Defrost cycle (normal)
Self-resolves in 5-15 minutes.
Likelihood 50%
- 2
Stuck reversing valve
Valve stuck in cool mode.
Likelihood 25%
- 3
Low refrigerant
Reduced or no heat output.
Likelihood 25%
What you can try first
- · Wait 15 minutes to see if defrost cycle resolves it
When to call us: Cold air persists for more than 30 minutes.
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 blowing cold air in heat mode dangerous?
Most causes of "heat pump blowing cold air in heat mode" are not immediately dangerous, but ignoring them can damage the system over time. Cold air persists for more than 30 minutes.
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.