How often should you service your air conditioner? Most split systems need a professional service once a year, and a clean of the filters every few weeks while the unit is in regular use. Book every six months if the system runs most days, if you have pets, or if the house is near a busy road, a building site or the coast. Ducted systems follow the same yearly rule, with the return air filter cleaned more often than a split system filter because it handles the air for the whole house.
This guide sets out the interval for each type of system, what changes it, what you can safely do yourself between services, and when to book in Melbourne so the unit is ready before you need it.
How often should a split system be serviced?
Once a year is the usual interval for a split system in a typical home. That service is when a technician cleans the indoor coil and fan, clears the drain line, checks the outdoor unit and confirms the system is heating and cooling properly.
Between services, the job that matters most is yours. Daikin, Mitsubishi Electric, Fujitsu and Panasonic all tell owners in their manuals to clean the air filters regularly, in most cases about every two weeks when the unit is in use. A clogged filter is a common reason a split system cools poorly, ices up or leaks water.
How often should ducted air conditioning be serviced?
Ducted systems should also be serviced once a year. The service covers more ground than a split system: the return air filter, the indoor unit in the roof or under the floor, the condensate drain, the outlets and the zone controls, plus the outdoor unit.
The return air grille is usually in a hallway ceiling. Check its filter every month or two in summer and winter. If it looks grey, it is already restricting airflow.
What changes the interval
| Your situation | Professional service | Filter cleaning |
|---|---|---|
| Light use, a few weeks a year | Every 12 months | At the start of each season, then monthly while in use |
| Typical home, summer and winter use | Every 12 months | About every two weeks while in use |
| Runs most days, or used for heating and cooling all year | Every 6 months | Every one to two weeks |
| Pets, smokers, a busy road or building work nearby | Every 6 months | Weekly while in use |
| Near the coast | Every 6 to 12 months, with the outdoor coil checked for corrosion | About every two weeks while in use |
| Home office, bedroom or nursery unit running long hours | Every 6 to 12 months | Every one to two weeks |
What you can do yourself between services
- Clean the filters. Switch the unit off, lift the front panel, slide the filters out, vacuum them and rinse in lukewarm water if they are greasy. Let them dry in the shade before refitting.
- Clear the outdoor unit. Keep leaves, plants and stored items at least a hand span away from the sides and well clear of the fan.
- Watch the drain. In cooling mode, water should drip from the drain hose outside. If it stops while the unit is cooling on a humid day, the line may be blocked.
- Listen and smell. A new rattle, a musty smell at start-up or ice on the pipes are all reasons to book a service early.
Do not spray cleaners into the indoor coil or open the outdoor unit. The coil fins bend easily, and the outdoor unit holds live electrical parts and refrigerant lines.
What a professional service covers
A proper service goes well beyond the filters. It usually includes cleaning the indoor coil and blower wheel, flushing the drain line, checking the outdoor coil and fan, testing the electrical connections and controls, and measuring how well the system is heating or cooling. Our air conditioner service page lists every step.
When is the best time to book in Melbourne?
Book in spring for cooling and in autumn for heating. September to early November gets the system ready before the first hot spell, and March to May gets a reverse cycle system ready for winter.
Booking early matters. The first 35 degree day of the season brings a rush of breakdown calls, and a unit that has sat unused for months often shows its faults that same afternoon.
Brand notes
- Daikin: many models show a filter reminder or a flashing lamp when the filter needs cleaning. Clear the reminder after cleaning. See our Daikin flashing green light guide.
- Mitsubishi Electric: the filters sit behind the front grille and slide up and out. Some models also have separate air-cleaning filters that are replaced rather than washed.
- Fujitsu: some models show a filter indicator after a set number of running hours. It does not mean something is wrong; clean the filter and reset the indicator.
- Panasonic: models with nanoe filtration still need the main dust filters cleaned. Before winter, run the unit in heat mode for a short while to check it before the first cold night.
Signs the unit needs attention before its next service
Weak airflow, water dripping indoors, a unit that keeps switching off, or a sudden jump in your power bill all mean the system should not wait for its yearly service. Our guide to the signs an air conditioner needs repair goes through each one.
If you would rather have it checked now, book a service online or call us and we will arrange an ARCtick-licensed technician.
To compare how much different models cost to run, check the star ratings on the Australian Government’s Energy Rating website.
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Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles