How often should you get your air conditioner serviced?

An air conditioner tends to get forgotten until the first hot week of summer, when it either struggles to keep up or doesn't start at all. A little regular care keeps it running efficiently, and a professional service catches small problems before they turn into a breakdown. This guide covers how often to service your system, what you can safely do yourself, and when to book a licensed technician.

How often should an air conditioner be serviced?

For most homes, the simple answer is once a year, before the season you rely on it most. The RACV notes that most air conditioner manufacturers recommend an annual service, and suggests booking a professional before summer starts, ideally in October or November. If you also use a reverse cycle system for heating, a second check in autumn before winter makes sense.

The Australian Government's energy.gov.au heating and cooling guide gives similar advice: get a regular service inspection before peak use, such as late spring or autumn, and have servicing done by a licensed technician.

Your own system may need more or less attention. Check the manufacturer's manual and your installation paperwork for the recommended service interval, especially if you want to keep the warranty valid. Systems that run most of the day, homes near the coast or on dusty roads, and households with pets that shed can all justify more frequent servicing.

What you can do yourself between services

There are two simple jobs most homeowners can handle without a tradie.

Clean the filters

The filters sit behind the front cover of a split system's indoor unit, or behind the return air grille on a ducted system. They catch dust before it reaches the coil and the air you breathe. The Victorian Government's heating and cooling buyers guide suggests cleaning the dust filters about twice a year, or more often if you use the unit regularly, and checking the manual for how to remove them.

A general routine:

1. Switch the system off at the controller.
2. Remove the filter and note which way round it goes.
3. Take it outside and shake or brush off the loose dust.
4. If the manual says it's washable, rinse it gently with plain water. Avoid harsh cleaning products.
5. Let it dry completely before you put it back.

If your system uses disposable filters, replace them rather than washing them.

Keep the outdoor unit clear

The outdoor unit needs air moving freely around it. Clear away leaves, grass clippings and rubbish, and trim back plants that are crowding it. energy.gov.au's summer guide also recommends keeping the area above an outdoor compressor clear for proper airflow and notes that shade can reduce the chance of it overheating.

Beyond that, leave the inside of the unit alone. Don't open up panels, spray chemicals into the coils or try to top up gas.

What a professional service should include

A proper service goes well beyond cleaning the filters. Exactly what's included varies between businesses, so ask before you book. A thorough service will usually cover:

• cleaning the filters, and the indoor and outdoor coils
• flushing and checking the condensate drain, so water doesn't leak inside
• checking the fan, motors and electrical connections
• checking the system is cooling and heating as it should
• checking for signs of refrigerant leaks
• checking the controller or thermostat
• on ducted systems, inspecting the ducts, vents and return air grille

Ask for a written summary of what was checked and any problems found. It's handy for your records and for any future warranty claim.

Who can service an air conditioner?

Most home split and ducted systems use fluorocarbon refrigerant gas, and working with it is regulated nationally. The Australian Refrigeration Council explains that anyone who handles refrigerant or works on refrigeration and air conditioning equipment must hold a refrigerant handling licence, and that this includes installing, servicing and maintaining the equipment. ARC's consumer site, Look for the Tick, says only licensed technicians can legally install and service fluorocarbon-gas air conditioners.

Not every licence covers every job. ARC's split system fact sheet explains that a restricted split systems licence covers installation and decommissioning, but not service or repair work that involves accessing or handling refrigerant. Electrical work on the system may also need a state electrical licence, so it's worth checking with your state regulator if you're unsure.

You can check a technician's refrigerant handling licence on the Look for the Tick licence check. To find someone local, browse our air conditioning directory or search by area, such as air conditioning in Sydney or air conditioning in Brisbane.

Signs your air conditioner needs attention now

Don't wait for the yearly service if you notice:

• rooms not cooling or heating the way they used to
• weak airflow, even with clean filters
• new rattling, grinding or squealing noises
• water dripping from the indoor unit
• a musty or burning smell when it runs
• ice forming on the pipes or the outdoor unit
• the system cycling on and off far more often than usual
• energy bills rising without a clear reason

If you smell burning or see scorch marks, switch the system off at the controller and the circuit breaker, and call a licensed technician or electrician before using it again.

Running it efficiently over summer

A well-maintained system is only part of the picture. How you use it matters too. According to energy.gov.au, setting your air conditioner between 25 and 27°C in summer helps, and every degree higher can save between 5 and 10% on energy costs. Closing internal doors to cool only the rooms you're using, and drawing blinds during the hottest part of the day, also reduce the load.

Getting a quote

Service prices vary with the type and number of systems, how easy the units are to reach, whether a deep clean is needed and where you live. Ask for two or three written quotes that spell out exactly what the service includes, and whether any extra work, such as a coil deep clean or a gas leak repair, would be quoted separately before it's done.

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Frequently asked questions

This guide is general information only, not legal or financial advice. Rules change, so check the official sources linked above for your state.