Heat Pump Not Cooling in Summer
Heat pump running but not cooling? Learn the common causes and solutions for heat pumps that won't provide cold air in summer.
24/7 Emergency Service • Same-day appointments • Free estimates on installations
Understanding the Problem
Heat pumps provide both heating and cooling by reversing the refrigeration cycle. When your heat pump won't cool in summer, it could be an issue specific to cooling mode or a general system problem that wasn't noticed during heating season. Many causes of heat pump cooling problems are similar to regular AC issues, but there are also heat-pump-specific problems like reversing valve failures.
Common Symptoms
You might be experiencing this problem if you notice:
- Heat pump runs but blows warm air
- Cooling is weak compared to previous years
- Heat pump cools sometimes but not consistently
- Outdoor unit fan runs but compressor doesn't
Possible Causes
This problem can be caused by several factors, listed from most to least likely:
Thermostat set incorrectly
Verify thermostat is set to cool with temperature below current room temperature.
Dirty air filter
Replace the air filter immediately.
Reversing valve stuck in heat mode
Professional diagnosis. May need valve replacement or solenoid coil.
Low refrigerant
Professional leak detection, repair, and recharge.
Dirty outdoor coil
Gently clean outdoor coils with garden hose. Remove debris.
Compressor issues
Professional diagnosis. May require compressor or system replacement.
DIY Troubleshooting Steps
Before calling a professional, try these safe troubleshooting steps:
- 1
Check thermostat settings (cool mode)
- 2
Replace air filter
- 3
Clean outdoor unit coils and remove debris
- 4
Check circuit breakers
- 5
Ensure all vents are open
- 6
Look for ice on refrigerant lines (indicates issues)
When to Call a Professional
Contact a licensed HVAC technician if:
- Thermostat is correct but unit blows warm air
- You suspect reversing valve problems
- Ice is forming on the system
- Outdoor unit makes unusual sounds
- DIY troubleshooting doesn't help
Prevention Tips
Help prevent this issue in the future with these maintenance tips:
- Schedule annual spring maintenance
- Change filters monthly during cooling season
- Keep outdoor unit clean and clear
- Address cooling issues early
Estimated Repair Cost
* Actual costs may vary based on the specific cause, parts needed, and system type. We provide upfront pricing before any work begins.
Need Help With This Issue?
Our expert technicians can diagnose and fix this problem quickly.
Call (650) 540-7205Book Service OnlineQuick Facts
- Category:heat-pump
- Urgency:Urgent
- DIY Fixes:3 of 6 causes
- Est. Cost:$0 (settings) to $400-$800 (reversing valve) to $500+ (refrigerant) to $2,000+ (compressor)
Related Problems
Services That Can Help
Ready for Expert HVAC Service?
Trane, Carrier & Mitsubishi HVAC Services is standing by to help with all your heating and cooling needs.
Same-day service available • No overtime charges • 100% Satisfaction Guaranteed