Even with their reputation for efficiency, heat pumps can sometimes encounter issues that affect performance. Whether your system is not heating, cooling, or behaving erratically, recognising early signs of trouble can help prevent long-term damage and unnecessary costs. In this blog, we look at common heat pump problems, what might be causing them, and when it’s time to call in a professional.
Diagnosing and Preventing Common Heat Pump Faults
Why Your Heat Pump Isn’t Heating Properly
Thermostat Errors
Always start with the thermostat. Make sure it's set to 'heat' rather than 'cool' and that the fan mode is set to 'auto', not 'on'. Incorrect settings are a common cause of poor performance.
Dirty Filters
Blocked filters restrict airflow, reducing your heat pump's efficiency and ability to warm your home. Filters should be cleaned or replaced every 1 to 3 months, especially during high-use seasons.
Low Refrigerant Levels
A refrigerant leak can reduce heating output, increase energy bills, and even lead to system damage. Ice on the outdoor unit or rising humidity indoors could signal this issue, which must be handled by a certified technician.
Outdoor Unit Obstruction
Check the outdoor unit for debris, vegetation, or even snow build-up. It needs clear airflow on all sides to function effectively.
When Cooling Stops Working
Dirty Coils
Both the indoor evaporator coil and outdoor condenser coil can get dirty over time, reducing cooling efficiency. While you can rinse the outdoor unit gently, internal coil cleaning should be left to professionals.
Refrigerant Issues
Leaks not only affect heating but also your cooling mode. Warm air from vents or a hissing sound could be early warnings. Never attempt to top up refrigerant yourself.
Constant Running Without Breaks
Incorrect Thermostat or Mode Settings
If your unit never switches off, check that it's not set to ‘emergency heat’ or a high target temperature. Also ensure the fan mode is not continuously running.
Restricted Airflow
Blocked filters or dirty coils force the heat pump to work overtime. Clean components can help it cycle on and off correctly.
Blowing Cold Air in Heating Mode
Thermostat Malfunction
A faulty thermostat may not be instructing the system to switch to heating mode. Try changing the batteries or updating the settings. If the issue persists, a replacement may be needed.
Refrigerant Leak
In heating mode, insufficient refrigerant can lead to lukewarm or cold air blowing from the vents. This is a sign to bring in a qualified engineer.
Water Leaks or Moisture Build-Up
Clogged Drain Line or Cracked Condensate Pan
When cooling, your heat pump removes moisture from the air. If the drainage system is blocked or the condensate pan is damaged, you might notice puddles near the unit.
Frozen Coils Melting
A refrigerant leak can cause coils to freeze. When the ice melts, it can mimic a water leak.
Electrical and Mechanical Failures
Compressor Issues
Noises, system shutdowns, or short cycling can point to a failing compressor. These are serious problems that require expert attention.
Wiring or Breaker Problems
If your heat pump suddenly stops working, check your circuit breaker first. If everything looks fine but the unit remains unresponsive, it could be a deeper wiring issue.
What You Can Check Yourself
Basic Checks
- Review your thermostat settings and fan mode
- Clean or replace air filters
- Remove any obstructions around the outdoor unit
- Listen for unusual sounds
- Look for visible ice on the unit
Advanced Checks (Only if Confident)
- Inspect indoor and outdoor coils for dirt
- Look for signs of leaks near pipe joints
- Check ductwork for disconnections
- Examine electrical connections for signs of corrosion
Heat pumps are reliable systems, but when they go wrong, quick action is vital. While some fixes are straightforward, many require professional expertise to resolve safely and effectively.
Looking for year-round peace of mind with your heat pump in Portsmouth and Hampshire?
GEO M&E Ltd offers expert repairs, system maintenance, and seasonal servicing to keep your heat pump performing at its best. Call us on 0239 238 8799 or fill out our contact form to schedule an inspection today.
