Key takeaways
- When summer arrives, you expect your heat pump to cool your home quickly and efficiently. If it only blows warm air or struggles to lower the room temperature, there are several possible causes.
- Some are easy to fix yourself, while others require professional diagnosis.
- Before assuming there's a fault, confirm the remote is set to Cooling mode.
When summer arrives, you expect your heat pump to cool your home quickly and efficiently. If it only blows warm air or struggles to lower the room temperature, there are several possible causes.
Some are easy to fix yourself, while others require professional diagnosis.
Check the Operating Mode
Before assuming there's a fault, confirm the remote is set to Cooling mode.
It's surprisingly common for the unit to remain in heating mode or fan-only mode after winter.
Also check that the temperature is set lower than the current room temperature.
Dirty Filters Restrict Airflow
Blocked filters reduce the amount of air moving across the indoor coil.
This makes cooling slower, increases electricity use and reduces overall comfort.
Cleaning the filters every few months is simple and can noticeably improve performance.
Doors and Windows
If warm outside air is constantly entering the home, the heat pump has to work much harder.
Keep windows and external doors closed while cooling and use curtains or blinds to reduce direct sunlight where practical.
Outdoor Unit Needs Airflow
The outdoor unit rejects heat to the outside air.
Leaves, vegetation or stored items placed around the unit reduce efficiency and can make cooling performance noticeably worse.
Refrigeration Problems
If the unit runs continuously but never becomes properly cold, the refrigeration system may require inspection.
Low refrigerant, sensor faults or other mechanical issues can all reduce cooling performance.
Only qualified technicians should work on sealed refrigeration systems.
When Should You Call Holmes Services?
Arrange a service if:
- The system blows warm air in cooling mode.
- Cooling has gradually become weaker.
- Ice forms on the indoor unit.
- The system runs constantly without reaching temperature.
- Error codes appear.
Early diagnosis often prevents more expensive repairs later.
Frequently asked questions
Why does my heat pump run but not cool?
Dirty filters, incorrect settings, restricted airflow or refrigeration faults are all common causes.
Will cleaning the filters help?
Yes. Clean filters improve airflow and efficiency, although they won't resolve refrigeration faults.
How often should a heat pump be serviced?
Most residential systems benefit from professional servicing every 12 months.
Need practical advice for your system?
Holmes Services helps Auckland homeowners and businesses with heat pumps, ventilation, refrigeration and indoor comfort issues.