Your heat pump is running. Air is coming out. But something's off. The room's not getting warm like it used to, or the system is taking twice as long to get there. You're starting to wonder if something's wrong.
In most cases, nothing is broken. Your system just needs a clean.
Knowing that before you call anyone matters. A repair technician can't fix a dirty heat pump, and that's a service job. Understanding which one you need saves you a call-out fee and gets the right person to your door.
Your heat pump has parts that need regular cleaning, and most homeowners have never seen them.
There's a filter inside the unit that catches dust and particles from the air in your home. It sits just behind the front panel. Over time it blocks up, and when it does, your system has to work harder to push air through. Most people don't know it's there until a technician opens the unit and shows them.
Behind the filter is the coil, a dense set of metal fins where the heating and cooling happens. Dust, moisture and organic growth build up on those fins over months. When they're dirty, your system can't heat or cool as effectively, so it runs longer to make up the difference.
The fan inside the unit pulls air through the coil and pushes it into the room. Dust builds up on the fan blades over time and reduces airflow. Your system works harder and sounds slightly different as a result.
Your outdoor unit does the same job as the indoor coil, but with the air outside. Leaves, grass clippings, cobwebs and general grime block the fins. A blocked outdoor unit slows the whole system down.
None of this happens overnight. The buildup is gradual. Most people notice something feels off long before they connect it to maintenance.
Your heat pump is still running, but it can't keep up. Air is coming out, it just isn't warm enough, or it's taking much longer than it used to. That's almost always a dirty filter, coil or outdoor unit slowing the system down. A professional service clears everything out and your system gets back to performing the way it should.
If your system is still producing some heat or cooling, even if it's weak, that points to a maintenance issue rather than a mechanical one.
Your system used to heat the room in 20 minutes. Now it takes 40 or more. The extra time isn't the unit getting old, it's the unit working harder because something is blocking it. Clean the components and runtime comes back down.
Your system is blowing air past surfaces that have mould or organic growth on them. That's where the smell comes from. It's usually on the coil or the fan inside the unit. A professional clean removes the growth and the smell goes with it.
A dirty heat pump runs longer to produce the same result. Blocked components can reduce your system's efficiency by anywhere from 10 to 25 percent. That extra runtime costs money every time the system runs. After a service, runtime drops and so does the bill. If your power bill has been climbing without an obvious reason, read why your power bill keeps climbing.
A higher hum, or a rattle that wasn't there before. Dust builds up on the fan inside the unit and throws it slightly off balance. The motor compensates and you hear the difference. A clean fan fixes it.
If any of those sound familiar, your system needs a professional service. All four components, the filter, coil, fan and outdoor unit, are cleaned in a single visit.
Some heat pumps display an error code on the indoor unit or remote when something goes wrong. If yours is showing one, it doesn't automatically mean you need a repairer.
Many error codes are triggered directly by maintenance issues. A blocked filter restricts airflow below the threshold the unit's sensors tolerate, and the system shuts down to protect itself. A blocked condensate drain causes water to back up and triggers a drain fault code. A coil that's built up enough grime to overheat the unit can trigger a thermal protection code. A service that addresses those faults often clears the code with them.
Some codes do point to electrical or mechanical faults. Fan motor failures, inverter faults, compressor problems, and communication errors between the indoor and outdoor units need a qualified repairer. A service can't resolve those.
If your unit is showing a code, a service is the right first step. The exception is if the system showed obvious signs of a mechanical problem before it shut down, such as grinding or clicking noises. More often then not, a professional service of the unit that addresses all of the common maintenance issues should resolve the error code. If your unit is a Daikin, our guide to Daikin heat pump fault codes and servicing covers how to retrieve the code from the remote and what each code indicates. Panasonic owners can retrieve the exact fault code stored in the unit's memory using the remote. why your Panasonic heat pump power light is flashing covers what each code is pointing to and how to decide between a service and a repair call.
There's one situation where a service won't help, and it's worth knowing before you book anything.
If your system is running but producing no heat at all in heating mode, air is moving but it's not warm, that's a different problem. The same goes for cooling: the unit is on, air is flowing, but nothing is cool.
That usually means your system has lost refrigerant. Refrigerant is the fluid that makes heating and cooling possible. Without enough of it, the system runs but does nothing useful.
Refrigerant leaks are more common in NZ than most homeowners realise, partly because some installations don't include proper pressure-testing of the pipework when the system is connected. A leak can develop slowly over a year or more before you notice anything. A service can't fix this. You need a licensed repair technician to find the leak, seal it and refill the refrigerant. If your system is producing no heat or cooling at all, contact a repair technician rather than booking a service. If your system is producing air that feels actively cold rather than just weak, there are a few distinct causes worth ruling out before you book anything. Why is my heat pump blowing cold air covers how to tell them apart.
For everything else, weak heating or cooling, longer warm-up times, musty smells, strange sounds, higher power bills, a service is the right starting point. For a full breakdown of what a professional maintenance visit covers, see heat pump maintenance Auckland.
Your clearest indicator is whether the system is still producing heat or cool air. If it's heating or cooling, even weakly, the problem is most likely dirty components and a service will address it. If your system is running but producing no heat in heating mode, or no cooling in cooling mode, that points to a refrigerant issue that a service can't fix.
MiHT's Home Energy System Health Assessment can help you identify if your system needs a service.
Yes, and most homeowners have never seen it. The filter sits just inside the front panel of your indoor unit. Its job is to catch dust, hair and airborne particles before they reach the internal components. It needs cleaning every four to six weeks during regular use, which is something you can do yourself. See how to clean a heat pump filter for the full process.
A blocked filter is one of the most common causes of reduced heat pump performance. A professional service goes further than the filter, cleaning the internal coil, fan and outdoor unit as well. How often should a heat pump be serviced in NZ.
Your heat pump runs longer when its components are dirty. A blocked filter, dirty coil or clogged outdoor unit forces the system to work harder to deliver the same amount of heating or cooling. That extra runtime uses more electricity. The efficiency loss can be anywhere from 10 to 25 percent depending on how long the system has gone without a service.
After a professional clean, runtime typically drops and your power consumption follows.
Don't assume it needs a repairer. Many error codes are triggered by maintenance issues: a blocked filter, a blocked condensate drain, or a coil that's overheated from years of buildup. A professional service addresses those causes, and the code often clears when the fault does.
Book a service unless the unit was making unusual mechanical noises, such as grinding or clicking, before it stopped. If the code clears after the service, the problem was maintenance-related. If it doesn't, the technician can advise whether an electrical or mechanical fault needs separate attention.
The filter, yes. Remove the front panel, take out the filter, rinse it under a cold tap and let it dry before putting it back. That's straightforward and worth doing every two to three months.
The internal coil, fan and outdoor unit are a different matter. They require specialist equipment and cleaning products to do properly without causing damage. A professional service covers all of those in a single visit.
Refrigerant is the fluid that allows your heat pump to heat or cool. A leak means it's escaping slowly through a small fault in the pipework. The clearest sign is a system that runs but produces no useful heat or cooling, not reduced output, but nothing at all.
If your system is still heating or cooling, even poorly, a leak is less likely. A refrigerant leak requires a licensed technician to diagnose and repair, it's not something a service can address.
Your heat pump is worth looking after properly. The Home Energy Health Assessment at MIHT Home Energy Care takes five minutes. It tells you where your system stands, what needs attention and what can wait. Start the Home Energy Health Assessment