Air Conditioner Maintenance: What to Do, and When to Call a Professional

Heating and cooling make up around 40% of the average Australian household's energy use, so a well-kept air conditioner is one of the simplest ways to keep your bills down. [1] Much of that upkeep you can do yourself, and regular professional servicing is often required to keep your manufacturer's warranty valid. Here is what every system needs, and where a licensed technician has to step in.

Why upkeep pays off. Common faults quietly waste energy, with typical losses of 14 to 20%, and when several build up at once, consumption climbs sharply and the risk of failure rises with it. [2] Staying on top of maintenance protects your efficiency, your running costs and, in many cases, your warranty.

Filters come first. A clean filter is the single most important maintenance task for any system, because a blocked one restricts airflow, drives up running costs and can freeze the indoor coil. Most Australian systems, both high-wall splits and ducted returns, use washable filters: rinse them every four to six weeks during regular use, or as often as fortnightly in heavy use. [3] If your ducted system uses disposable media filters instead, check them on the same schedule but expect to replace them every few months, or sooner if they're visibly clogged.

Never reinstall a damp filter. Washable filters must dry fully before they go back in, because a damp filter becomes a breeding ground for mould and bacteria that then circulate through your home. Ducted systems can use disposable filters instead, which remove that risk and the washing altogether.

Keep the outdoor unit clear. Airflow drives efficiency, so keep leaves, dirt and vegetation away from the unit and leave roughly 500mm of clearance on all sides. If the fins are dusty, switch the unit off at the isolator first, then rinse the finned coil gently with a low-pressure hose, keeping water away from the isolator and any wiring. Never use high pressure, which bends the fins. For a deeper coil clean, book a licensed technician as part of your regular service.

Set sensible temperatures. Every extra degree of heating or cooling adds around 5 to 10% to your energy use. [1] You don't need to suffer through an uncomfortable house, but even a one or two degree adjustment toward moderate makes a real difference to your bill. And resist setting extremes to heat or cool faster: your system runs at the same rate regardless, so a very low or high setpoint doesn't speed anything up, it just overshoots and wastes energy.

Evaporative coolers need seasonal care. Clean the cooling pads and filter at the start of each cooling season and monthly during use, and replace any pads that are crumbling or heavily mineralised. [4] At the end of the season, cover the roof unit and close off the ducts, which stops cold air entering through the system and lifting your winter heating costs. [4]

Know the warning signs. Book a licensed technician if you notice unusual noises, weak airflow, the system running without reaching the set temperature, water dripping indoors, ice forming on the unit or refrigerant lines, or an unexplained jump in your power bill. Each points to a fault that needs professional diagnosis.

Some work is licensed only. All refrigerant handling and electrical work must be carried out by a technician licensed through the Australian Refrigeration Council (ARC). [5] Ducted air distribution maintenance also follows the AS/NZS 3666.2 standard. [6] Refrigerant, electrical, drainage and ductwork repairs are not DIY jobs.

Service on schedule. Have refrigerated systems, both split and ducted, professionally serviced about every 12 months, ideally before peak season. [6] Evaporative coolers need a professional every two to three years to de-scale the pads, check the pump, adjust the fan belt and set the bleed rate. [4]

AC Wise connects you with vetted, licensed air conditioning professionals across Australia, for routine servicing, fault diagnosis, filter upgrades and full system inspections. Request a service from an AC Wise partner.