Quick Answer

Service your air conditioner once a year — ideally in autumn before heating season, or spring before the first hot spell. DIY tasks include cleaning or replacing filters every 1–3 months and wiping down the indoor unit. A full professional service (refrigerant check, coil clean, electrical test) costs $150–$300 for a split system and should be done annually. Skipping service increases running costs by 10–15% and cuts the unit’s life by years.

Cleaning a split system air filter — a blocked filter forces the compressor to work harder, increasi
Cleaning a split system air filter — a blocked filter forces the compressor to work harder, increasing power bills by up to 15% and shortening the unit’s life; this simple task takes under five minutes and should be done every 4–6 weeks during heavy use.

Why Regular Air Conditioner Servicing Matters

An air conditioner that hasn’t been serviced in two or three years is working harder than it needs to. Dirty filters restrict airflow, forcing the compressor to run longer. Dirty coils reduce heat exchange efficiency. Low refrigerant (from small leaks) causes the unit to struggle in peak heat or cold. The result: higher electricity bills, a shorter lifespan, and more frequent breakdowns — usually at the worst possible time.

In Melbourne’s climate, most split systems and ducted systems run for 4–6 months of the year. Without maintenance, the average lifespan of 15–20 years shrinks to 10–12 years — effectively halving your return on a $1,500–$6,000 investment.

Air Conditioner Service Schedule

Monthly (During Use Period)

Task Who Time
Wipe indoor unit casing with damp cloth DIY 5 minutes
Check air vents are unobstructed (furniture, curtains) DIY 2 minutes
Listen for unusual noises (rattling, squealing) DIY Ongoing

Every 4–6 Weeks (During Heavy Use)

Task Who Cost
Remove and clean indoor filter DIY Free (rinse under tap, air dry)
Vacuum dust from filter housing DIY Free
Check condensate drain tray for overflow or mould DIY Free

Every 3 Months

Task Who Notes
Inspect outdoor unit — clear leaves, debris from around unit DIY Keep 600mm clearance on all sides
Check outdoor unit fins for damage or blockage DIY Do not bend fins; use fin comb if needed
Test remote control and temperature response DIY Replace remote batteries if sluggish

Annual Professional Service

Task Who Cost
Deep clean evaporator and condenser coils Licensed HVAC tech Included in service fee
Check and top up refrigerant (if needed) Licensed refrigeration tech (ARC tick) $80–$200 extra if low
Inspect and test electrical connections Licensed HVAC tech Included in service fee
Check condensate drain and flush clear Licensed HVAC tech Included in service fee
Inspect fan blades and motor Licensed HVAC tech Included in service fee
Test heating and cooling in both modes Licensed HVAC tech Included in service fee
Full service report and filter replacement (if required) Licensed HVAC tech $150–$300 total for split system
Pro tip: Book your annual service in autumn (March–May) rather than spring. HVAC technicians are flat-out in September–October as everyone scrambles to prepare for summer. Autumn bookings get faster response times and sometimes cheaper rates.
Clearing leaf litter from around an outdoor compressor unit — debris restricts airflow to the conden
Clearing leaf litter from around an outdoor compressor unit — debris restricts airflow to the condenser coils, reducing cooling efficiency and causing the unit to run longer to reach the set temperature.

How to Clean Your Air Conditioner Filter (DIY)

Cleaning the filter is the single most effective maintenance task a homeowner can do and takes less than five minutes. Most split systems have filters that slide out from behind the front panel of the indoor unit.

  1. Turn the unit off at the remote and at the wall switch before opening the panel.
  2. Lift or slide the front panel — most panels hinge upward or clip down from the top.
  3. Slide out the filter — there are usually two mesh filters side by side.
  4. Vacuum loose dust with the brush attachment of a vacuum cleaner.
  5. Rinse under warm water — run from the clean side to push dust out through the dirty side. Do not use soap or spray cleaners unless the filter is genuinely greasy.
  6. Air dry completely — lay flat in the shade. Never put a wet filter back into the unit; mould can form inside the housing within 48 hours.
  7. Reinstall and test — the unit should move air more freely and reach the set temperature faster.
Safety warning: Never attempt to clean the coils (the silver/aluminium fins behind the filter) yourself with high-pressure water or spray cleaners. This can bend the fins, push moisture into electrical components, or void your warranty. Coil cleaning requires a licensed HVAC technician with appropriate equipment and chemicals.

Signs Your Air Conditioner Needs a Service Now

Symptom Likely Cause Action
Weak airflow despite fan on high Blocked filter or dirty coils Clean filter; book professional coil clean
Warm air from cooling mode Low refrigerant or dirty condenser Book licensed refrigeration technician
Water dripping from indoor unit Blocked condensate drain DIY drain flush; or call technician if persists
Musty or mouldy smell on startup Mould on evaporator coil or drain pan Book professional coil clean and mould treatment
Rattling or squealing noises Loose fan blade or failing motor bearing Turn off unit; call technician immediately
Unit cycling on and off rapidly Dirty coils, low refrigerant, or faulty thermostat Book professional service
Ice on the indoor unit or pipes Restricted airflow or low refrigerant Turn off immediately; call technician

Cost of Professional Air Conditioner Servicing in Melbourne

Service Type Cost (Melbourne 2026) Includes
Split system annual service $150–$300 Filter clean, coil clean, electrical check, test
Ducted system annual service $250–$500 All zones checked, filters, duct inspection
Refrigerant top-up (R410A) $80–$200 extra Leak test, recharge to manufacturer specification
Coil deep clean (chemical) $100–$200 extra Foaming chemical cleaner, rinse, deodoriser
Multi-system service (3+ units) $100–$200 per unit Quantity discount typically available

Ducted Air Conditioning: Extra Maintenance Steps

Ducted systems have more components to maintain than split systems. In addition to the main unit service, ducted system owners should:

  • Replace return air filters every 3–6 months — the return air grille (usually ceiling-mounted) has a replaceable filter that catches dust before it reaches the main unit. A blocked return filter reduces airflow across the whole system.
  • Check zone dampers annually — zone dampers can fail in open or closed positions, causing rooms to be over-cooled or excluded entirely.
  • Inspect flexible duct runs — in homes with flexible ducting in the ceiling cavity, check for kinks, disconnections, or rodent damage during the annual service.
  • Clean ceiling diffusers — the louvres in each room’s ceiling grille accumulate dust. Remove and wipe down with a damp cloth each year.

Top 10 Air Conditioner Maintenance Tips

  1. Set a phone reminder to clean the filter. Every 4–6 weeks during heavy use, every 3 months otherwise. One reminder prevents the most common maintenance failure.
  2. Never obstruct the outdoor unit. Keep 600mm of clearance on all sides and top. Pergolas, fences, and plants all reduce airflow and efficiency.
  3. Use “auto” mode, not fixed fan speed. Auto mode runs the fan at the speed needed — less wear on the motor during mild conditions.
  4. Set the thermostat to 24°C in summer, 21°C in winter. Every degree above 24°C (cooling) or below 21°C (heating) adds approximately 10% to running costs.
  5. Use the timer function. Pre-cool or pre-heat the house before you arrive, then turn off when you leave. Avoid leaving the unit running all day in an empty house.
  6. Only a licensed technician can legally handle refrigerant. In Australia, refrigerant handling requires an ARC (Australian Refrigeration Council) licence. Never allow unlicensed work — it voids warranties and is illegal.
  7. Check the drainage line after heavy rain. Some outdoor units have drainage lines that can become blocked with debris during storms, causing water backup into the system.
  8. Don’t close too many zone vents in ducted systems. Closing more than 30% of zone vents creates excessive pressure that strains the fan motor and can crack duct seals.
  9. Service before warranty expires. Most manufacturers require documented annual servicing to maintain warranty. Keep service receipts.
  10. Consider a service contract. Many HVAC companies offer annual service contracts for $100–$180 per year that include priority booking, discounted call-outs, and parts discounts.
A heavily soiled return air filter from a ducted system — this level of blockage reduces airflow acr
A heavily soiled return air filter from a ducted system — this level of blockage reduces airflow across the entire house and forces the compressor to run continuously, adding hundreds of dollars a year to electricity bills.

Local Melbourne Resources

Frequently Asked Questions

How often should a split system air conditioner be serviced professionally?

Once a year is the standard recommendation for residential split systems. Heavy-use units in larger families or coastal properties (where salt air accelerates coil corrosion) benefit from twice-yearly servicing. Check your manufacturer’s warranty terms — many specify annual servicing to maintain warranty coverage.

Can I service my own air conditioner, or do I need a licensed technician?

You can clean filters, wipe the casing, and clear debris from around the outdoor unit — all DIY tasks. However, coil cleaning with chemicals, refrigerant checks or top-ups, and electrical component inspection require a licensed HVAC technician. Refrigerant handling specifically requires an ARC (Australian Refrigeration Council) licence under Australian law.

Why does my air conditioner smell musty when I first turn it on?

Mould and bacteria growing on the evaporator coil — particularly in the moist environment that develops during cooling — is the most common cause. A professional coil clean with antibacterial treatment resolves the smell. Clean the filter immediately as a first step; if the smell persists, book a coil clean.

How long should a split system air conditioner last?

A well-maintained split system should last 15–20 years. Units that are serviced irregularly typically fail at 8–12 years. The compressor is the most expensive component to replace, often costing 50–70% of a new unit’s price — which is why annual servicing is such good value compared to premature replacement.

What does it mean when my air conditioner has ice on it?

Ice on the indoor unit or refrigerant pipes indicates severely restricted airflow (blocked filter or coil) or critically low refrigerant. Turn the unit off immediately to prevent compressor damage. Clean the filter and check airflow first; if ice returns after defrosting and restarting, call a licensed refrigeration technician — the unit likely needs a refrigerant recharge.

Final Thoughts

A $150–$300 annual service is cheap insurance against a $500–$1,500 breakdown repair or a $1,500–$6,000 premature replacement. The biggest single thing most homeowners can do is simply clean the filter every 4–6 weeks during the cooling and heating seasons. It takes five minutes and makes a measurable difference to airflow, efficiency, and indoor air quality.

Book your annual professional service in autumn, keep your service records, and follow the manufacturer’s filter cleaning schedule. In Melbourne’s climate, a well-maintained air conditioner is one of the most cost-effective home appliances you own.