When a heat pump stops working properly in the middle of a Dunedin winter, it does not always mean the unit has failed. Sometimes the cause is simple, such as an incorrect setting or dirty filter. Other problems, including refrigerant leaks, electrical faults or persistent icing, need professional attention.
At McClelland Refrigeration, we work on heat pumps throughout Dunedin and Otago, so we regularly see the effects of cold winters, frost, coastal air and older housing on system performance.
Here are some of the most common heat pump problems, what you can check yourself, and when it is worth booking a professional heat pump service.
Your Heat Pump Is Running but Not Heating Properly
If your heat pump is running but the room is not getting warm, start with the settings. Make sure the unit is on HEAT mode and the selected temperature is above the current room temperature. If the settings are correct, check the filters. Dust and debris can restrict airflow and reduce heating performance.
A system that still struggles after these checks may have a technical fault or may not be correctly sized for the space. Our guide to troubleshooting common heat pump issues covers additional checks you can make before arranging a repair.
Dirty or Blocked Heat Pump Filters
Dirty filters are one of the most common and preventable causes of poor heat pump performance. As dust builds up, airflow drops and the system has to work harder to heat or cool the room. You may notice weaker airflow, longer running times or reduced comfort.
We recommend checking the filters regularly and cleaning them according to the manufacturer’s instructions. If airflow remains poor after cleaning, the system may need a more thorough professional clean or inspection.
The Outdoor Unit Keeps Icing Up
Some frost on the outdoor unit during a cold Dunedin morning is normal. Heat pumps periodically enter a defrost cycle to remove it. The concern is heavy or persistent ice that does not clear.
If the unit stays iced up or heating performance drops significantly, check that leaves, plants or debris are not restricting airflow around the outdoor unit. Ongoing icing can also indicate a sensor, airflow, refrigerant or defrost-system issue.
For properties near the coast, our guide to caring for heat pumps in Dunedin’s salt air explains how local conditions can affect outdoor components over time.
Your Heat Pump Is Leaking Water
Water around the outdoor unit can be normal, particularly during a defrost cycle. Water leaking from the indoor unit is different and should be investigated.
Common causes include blocked drainage, dirt buildup or problems with the original installation. If the leak continues, it is best to have the system checked before moisture damages nearby walls or flooring. Correct drainage is also an important part of professional heat pump installation.
The Heat Pump Is Making Unusual Noises
Heat pumps make some normal operating sounds, especially when starting, stopping or defrosting. New grinding, buzzing, rattling or excessive vibration can point to loose components, fan problems, electrical faults or mounting issues.
If the noise is new, persistent or getting louder, it is worth having the unit checked before a minor issue becomes a larger repair.
The Heat Pump Won’t Turn On
If your heat pump will not start, check the basics first. Make sure the remote batteries are working, the correct mode is selected, and the system has power.
If a circuit breaker has tripped, resetting it once may solve an isolated problem. If it trips again, do not keep resetting it. Repeated tripping can indicate an electrical or equipment fault.
Your Heat Pump Is Running Constantly
Long running times are not always a problem, especially during a cold Dunedin winter. However, if the heat pump runs continuously and still cannot reach the selected temperature, something may be reducing its efficiency.
Possible causes include dirty filters, restricted airflow, poor insulation or an undersized system. If your electricity use has also increased noticeably, it may be worth having the unit assessed. Our guide to heat pump running costs in Dunedin explains how sizing, settings, and maintenance can affect energy use.
Refrigerant Problems or Leaks
Refrigerant transfers heat through the system and should not normally need regular topping up.
If refrigerant levels are low, there may be a leak or another system fault. Possible signs include poor heating or cooling, icing, and reduced performance. Refrigerant issues should be diagnosed by a trained technician rather than treated by simply adding more refrigerant.
Poor Installation or Incorrect Heat Pump Sizing
Sometimes the heat pump itself is not faulty. The issue is how it was selected or installed. An undersized unit may run constantly without adequately heating the room. Poor placement can also contribute to uneven temperatures, noise, drainage problems or restricted airflow.
This can be especially important in Dunedin homes with high ceilings, draughts, older insulation or exposed coastal locations. If your heat pump has never performed properly, it may be worth having the sizing and installation assessed rather than assuming the unit needs replacing.
When Should You Book a Heat Pump Service?
We recommend arranging an inspection if your heat pump:
- still is not heating properly after basic checks
- repeatedly trips the power
- develops heavy ice that does not clear
- leaks water inside
- makes new or unusual noises
- has noticeably weaker airflow
- runs continuously without reaching temperature
- suddenly costs more to operate
- stops working altogether
Regular servicing can also help identify developing problems before they turn into breakdowns.
Need Help With a Heat Pump Problem in Dunedin?
If your heat pump is not performing as it should, we can help determine whether the problem is routine maintenance, a repairable fault or an installation issue.
At McClelland Refrigeration, we install and service heat pumps throughout Dunedin and the wider Otago region.
Request a heat pump service and we can assess what is causing the problem.
