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.
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.
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.
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.
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 two to three months, which is something you can do yourself by removing the front panel and rinsing the filter under a tap.
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.
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