How Often Should You Service Your Heat Pump?

Heat pumps do most of the heavy lifting in NZ homes: warming us in winter, cooling us in summer, running year-round. But how often do they actually need servicing? Skip it too long and efficiency drops, bills rise, and the unit’s life gets cut short. Here’s what NZ homeowners need to know.

The short answer: once a year

For most residential heat pumps, an annual professional service is the sweet spot. It keeps the unit running efficiently, catches small issues before they become expensive, and protects your manufacturer warranty. Most brands (Mitsubishi, Daikin, Panasonic, Fujitsu) either recommend or require annual servicing to keep the warranty valid.

Commercial heat pumps, or units that run hard in extreme climates, may need servicing every six months. Homes near the coast also benefit from more frequent checks because salt air accelerates corrosion on outdoor units.

What happens during a professional service

A proper heat pump service is more than a wipe-down with a cloth. A qualified technician should do all of the following:

• Deep clean the filters and indoor coil
• Check refrigerant pressure and top up if needed
• Inspect the outdoor unit for debris, leaves and bird nests
• Clean the outdoor coil and clear drainage
• Check electrical connections and safety controls
• Test thermostat and sensor accuracy
• Run the system in both heating and cooling mode to check performance
• Sanitise the indoor unit to prevent mould and odours

A good technician will give you a written report and flag any issues before they become serious.

What you can do between services

You don’t need to wait 12 months to touch your unit. Homeowner maintenance keeps things running well between professional services. Think of it like a mini-service you do yourself every four to six weeks during heavy use.

Monthly DIY checks

• Pull out and wash the indoor filters (warm water, mild detergent, air dry)
• Wipe down the exterior of the indoor unit
• Check the outdoor unit is clear of leaves, grass clippings and rubbish
• Listen for any unusual rattling, buzzing or gurgling sounds
• Feel the airflow: weak or warm air on cooling mode signals a problem

Clogged filters are the number one cause of reduced heat pump efficiency. They force the unit to work harder, chew through power and wear out components faster. Five minutes a month saves real money.

Signs your heat pump needs urgent attention

Some issues can’t wait for the annual service. Call a technician sooner if you notice:

• Water dripping or pooling under the indoor unit
• Ice forming on the indoor or outdoor coils
• Musty, damp or burning smells when the unit runs
• Sudden drop in heating or cooling performance
• Strange noises (grinding, screeching, loud clicking)
• Power consumption climbing without any change in use

Running a faulty unit can cause further damage. At best you’ll need a bigger repair. At worst you’ll be replacing the whole system years earlier than planned.

Why regular servicing pays for itself

An annual service costs a lot less than a call-out for a failed unit, let alone a full replacement. The numbers stack up pretty clearly:

• Efficiency: A dirty heat pump can use 10 to 25 per cent more power to deliver the same output. That’s hundreds of dollars a year on a family-sized system.
• Lifespan: Serviced heat pumps typically last 15 to 20 years. Neglected ones often give up at 8 to 10.
• Warranty: Most manufacturers require documented annual servicing. Skip it and a big-ticket repair may not be covered.
• Air quality: Mould and bacteria build up in neglected units. Serviced units blow cleaner air, which matters for anyone with asthma or allergies.

When to book your service

The ideal time is late summer or early autumn, just before the unit starts working hard for winter. Technicians are less booked up, prices are competitive, and you head into the cold season knowing everything’s sorted.

If you’ve missed that window, any time is better than no time. Even a mid-winter service is worthwhile if your last one was a couple of years back.

Who to book

Heat pump servicing should be done by a technician with proper refrigeration and electrical qualifications. In NZ, this usually means someone with an NZQA refrigeration qualification and EWRB registration for the electrical components.

Ask about:

• Qualifications and insurance
• Experience with your brand and model
• Whether the service includes a written report
• Workmanship warranty on any repairs
• Total cost, including GST and travel fees

A small habit that saves big money

Annual heat pump servicing is one of those quiet home maintenance habits that saves you real money over the years. Book it in, add it to your calendar, and forget about it. Your heat pump will run better, last longer, and keep your power bills in check.

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