By Steve, co-founder AC Store | Published: 8 September 2026 | Last updated: 8 September 2026
It’s mid-September in South East Queensland. This weekend, thousands of Brisbane, Moreton Bay and Sunshine Coast homes turned the aircon on for the first time since Easter and got hit with a mouldy waft they don’t remember from last summer. The good news: 15 minutes and a garden hose fixes 80% of it.
Short version. For a split system: open the front panel, lift out the filter mesh, vacuum it, rinse under cool tap water (a splash of dish soap if grimy), dry fully, refit, and reset the filter warning on the remote. Do it monthly through SEQ summer (Dec–Feb), and every 2–3 months the rest of the year. For a ducted system: pull down the return-air ceiling grille (usually in the hallway) and do exactly the same. Neither job takes more than 20 minutes.
Across 10,000+ SEQ installs, nine out of ten September “my split isn’t cooling like it used to” calls end the same way: pull the filter, clean it properly, re-check. This is the guide, split-and-ducted, brand-by-brand. Book a pre-summer service if you’d rather have it done properly.
Why filter cleaning matters more in South East Queensland than anywhere else
SEQ sits in BCA Climate Zone 2: subtropical, humid, high pollen, long cooling season. Filters load faster here than in Melbourne or Adelaide, and mould grows in the pan and on the coil months faster too. The 2025–2026 wet season and the aftermath of ex-tropical cyclone Alfred left many homes with elevated indoor humidity, so filters that have sat damp since April have grown more mould than usual.
A clogged filter drops cooling output 5–15% and lifts your power draw the same amount. On a $2,400/year summer power bill that’s $120–$360 wasted. A monthly filter rinse is the single highest-ROI thing any homeowner can do. Everything else is fair game to hand to us.
How to clean a split system filter
What you’ll need
Soft-brush vacuum attachment, cool tap water (never hot; it warps the frame), a splash of mild dish soap for grimy kitchen-adjacent filters, a microfibre cloth, and about 15 minutes. No bleach, no kitchen degreasers, no pressure washer.
Step-by-step (6 steps, 15 minutes)
1. Power down at the wall. Off with the remote first, then flick the wall isolator. Mistake we see most: skipping the isolator and getting a face full of fan start-up while the filter’s half out.
2. Open the front panel. Lift the hinged cover up from the bottom edge until it catches. Snap a phone photo before you touch anything, this makes refitting foolproof.
3. Lift the filter mesh out. Two clips or a slide-out frame, filthy on the room-facing side, clean on the coil side. If the unit has a secondary filter behind the main mesh (Plasma, Titanium Apatite, ioniser cartridge), note its position but leave it for now, those only need attention once a year.
4. Vacuum first, then rinse. Vacuum the loose dust off the dirty side over a bin. Rinse under cool water from the clean side outward, pushing dust back out. A splash of dish soap on a grimy kitchen filter, gentle rub, rinse off. Never force water at high pressure: you’ll stretch or split the mesh.
5. Dry fully in the shade. Lay flat in the shade for 30–60 minutes until bone dry. A wet filter back in the unit equals instant mould, especially in SEQ humidity. Don’t use a hair dryer or put it in direct sun: heat warps the plastic frame.
6. Refit and reset the warning light. Slide the filter back in, close the panel until it clicks, switch the isolator on, then hold FILTER RESET on the remote for 3 seconds. On ducted controllers it’s usually under Menu → Filter. Done.
How often, in SEQ
Monthly December to February when it’s running hard. Every 2–3 months the rest of the year. Coastal homes, near unsealed roads or construction, or if you have pets, lean toward monthly year-round.
How to clean a ducted system filter
Find your return-air grille
On most Australian ducted homes the filter is behind the largest ceiling grille, usually in a central hallway. It clips out without tools. The smaller grilles in bedrooms and living areas are supply-air outlets. Don’t have a visible return? Check for a ceiling cupboard or laundry ceiling vent.
Step-by-step (5 steps, 20 minutes)
1. Switch off at the wall controller AND the isolator. Ducted systems draw high current and an unexpected start during cleaning is not something you want to test.
2. Release the return-air grille. Two thumb-clips, magnets or hinges. The grille drops on a safety chain or lifts out entirely. Watch for dust fall.
3. Slide the filter out. Large (often 600 × 400 mm) and heavy with dust, hold it flat, take it outside before you shake it off.
4. Vacuum, rinse, dry. Same routine as a split filter, vacuum first, rinse under cool water from the clean side, dry flat in the shade until bone dry.
5. Refit and re-clip the grille. Slide the dry filter back into its tray, lift the grille up, refit clips, switch system back on.
When to replace instead of clean
If the grille filter is a thin foam pad that disintegrates in your hand, replace it. Most ducted return-air filters are cheap, standard-sized polyester pads available from any aircon supplier including AC Store. A new one every 12 months is cheap insurance.
What NOT to clean yourself on a ducted
The in-ceiling fan coil, the in-roof plenum and the condensate pump are hands-off for homeowners. They need a licensed tech and proper access. If your ducted system smells after a filter clean, it’s usually the coil or drain pan growing something in the dark.
Brand-specific quick reference, filter access and warning-light reset
Each major brand sold in AC Store’s range does filter access slightly differently. Here’s the quick reference. Verify current model-year procedure against your remote manual; Daikin in particular tweaks reset steps between L-series, Cora and M-series.
| Brand | Filter access + warning-light reset | One thing we see get missed |
|---|---|---|
| Daikin | Hinged front panel, mesh on two clips. Hold FILTER RESET on the remote for 3 seconds after refitting. | The warning is a running-hours timer, not a dirt sensor, a quick vacuum without properly rinsing doesn’t reset the dust problem even though the light goes off. |
| LG | Panel lifts, mesh slides out. Dual-inverter models have a Plasmaster ioniser element behind the pre-filter: wipe it monthly with a dry cloth. | Treating the ioniser element like a washable filter. |
| Mitsubishi Electric | MSZ front cover flips up, mesh clips out. Hold the RESET pin on the indoor unit or use the remote’s filter-reset function. | The nano-platinum filter behind the pre-filter is a 10-year consumable, not a wash-and-reuse. |
| Fujitsu | Lifestyle Range panel opens on two clips. Reset varies by remote model; most: hold FILTER for 3 seconds. | Coastal units (within 5 km of the beach) load filters twice as fast due to salt and sand. |
| Panasonic | Panel opens, mesh lifts. Nanoe-X models have a Nanoe generator inside the unit; leave it alone. | Confusing the Nanoe cartridge with a filter. |
| Samsung | Wind-Free: front grille clips off entirely to access the mesh. Filter reset via remote. | Wind-Free micro-holes on the face panel clog with dust, wipe the face panel too. |
| Midea | Standard hinged front panel. Reset via FILTER on the remote. | Outdoor units also collect leaves quickly, clear at the same time. |
| AirTouch (ducted) | Filter’s behind the ceiling return grille, not in the controller. Same vacuum-rinse-dry cycle. | Cleaning supply grilles thinking they’re the filter, only the return-air grille has the filter. |
If your filter warning light keeps flashing after a clean and a reset, that’s a signal to book a service: the timer might not be the real problem.
What to buy at Bunnings, and what to skip
Bunnings is where most SEQ homeowners buy their cleaning kit. A lot of aircon-cleaning products are on the shelf now, and not all of them are good for your unit.
Worth grabbing. A soft-brush vacuum attachment (Nifti and HG both make cheap ones), a garden sprayer for gentle rinsing, microfibre cloths, and mild dish soap. That’s the full kit.
Situational. Foaming coil cleaners (Actrol, Aeroguard-style cans) do a reasonable job on a lightly dusty coil and are fine as a between-services top-up. They don’t flush the drain or reach the deep coil, so they’re a supplement, not a replacement for a proper service.
Skip. Bleach (destroys the mesh and corrodes downstream metal), harsh degreasers, and high-pressure water. All three cause more damage than they fix.
When DIY isn’t enough, and what a proper service actually covers
A monthly filter rinse handles the front line. A proper service handles the rest.
Book a service when: the mouldy smell persists after a proper filter clean; visible black staining on the coil behind the filter; water dripping from the indoor unit; ice on the copper coil; the filter warning comes back within days of resetting it; or the system is 3+ years old and has never been professionally serviced.
What our maintenance team does that DIY can’t: evaporator coil deep clean (coil bath + non-drip sanitiser), blower wheel clean (needs the fan cage pulled), condensate drain flush, drain pan sanitise, refrigerant pressure check, electrical safety check, and, on coastal Sunshine Coast and Hervey Bay properties, a proper outdoor condenser wash-down.
A full pre-summer service is fixed price, protects your manufacturer warranty on most premium brands, and takes the last 20% off the summer bill that a filter clean alone can’t reach. Book a maintenance service →
Should you replace instead of servicing?
Sometimes cleaning is money after the fact. Honest triggers we tell customers to replace, not repair:
- 10+ years old and needing its second-in-two-years service.
- R410A unit (check the outdoor sticker) due for a regas. R410A prices keep climbing and R32 units are cheaper to run and service long-term.
- Ducted system with recurring drain issues and a rusted drain pan.
- Split with a corroded coastal condenser that’s lost 30%+ of fin area.
2026 SEQ indicative replacement pricing (verify with sales): single-head split supplied and installed $2,500–$4,500; multi-head 3-zone $6,500–$11,000; ducted 4–6 zone $10,000–$18,000; premium ducted with AirTouch zoning $15,000–$25,000.
Our 12–60 month interest-free finance turns a $12,000 ducted upgrade into around $200/month at 0%, subject to approval and finance-page terms. Come see a modern R32 inverter running against a tired 2015 unit at our North Lakes or Kawana showroom, or request a free split or ducted quote.
Frequently Asked Questions
How often should I clean my aircon filter in Queensland?
Monthly through summer (December–February) and every 2–3 months the rest of the year. Coastal homes (Sunshine Coast, Hervey Bay) and homes near unsealed roads load faster. Use it daily and never clean it, and airflow drops noticeably by the end of the first summer.
Can I wash my split system filter under the tap?
Yes: cool tap water only. Vacuum the loose dust off first, then rinse from the clean side outwards so you push dust back out rather than through the mesh. A splash of mild dish soap is fine for greasy kitchen-adjacent filters. Never hot water (warps the frame), and never bleach (damages the mesh).
How do I turn off the filter warning light on my Daikin remote?
Hold FILTER RESET on the remote for 3 seconds after refitting; the light on the indoor unit stops flashing. On ducted BRC-series controllers it’s under Menu → Filter. If it keeps flashing, the timer might not be the real problem, so it’s worth a service call.
Where is the filter on a ducted air conditioner in Australia?
Behind the largest ceiling grille, usually a central hallway. It clips out; no tools needed. There isn’t a filter in each room grille (those are supply-air outlets). If you can’t find your return, it may be inside a ceiling cupboard or on the laundry ceiling.
Is it worth paying for a professional aircon service in Brisbane?
For a system 3+ years old that’s never been professionally serviced, yes. DIY only reaches around 40% of what a full service does: coil, drain, blower, refrigerant and electrical safety all need pro tools and (for refrigerant work) an ARCtick licence. A pre-summer service in SEQ typically pays back within one or two summer power bills.
Does cleaning the filter stop the mouldy smell?
Sometimes. If the smell is in the filter mesh alone, a clean fixes it. If it’s on the evaporator coil, the drain pan or the blower wheel (common in SEQ after humid summers), it’ll be back within a week. Persistent mould smell after a filter clean is our #1 September call-out trigger.
Can I use a Bunnings aircon cleaning spray?
Foaming coil cleaners do a reasonable job on a lightly dusty coil and are fine as a between-services top-up. They don’t flush the drain, clean the blower wheel, or reach the deep coil sections where SEQ humidity grows biofilm. Supplement to a proper service, not a replacement.
Will regular servicing keep my manufacturer warranty valid?
On most premium brands sold in Australia (Daikin, LG, Fujitsu, Mitsubishi Electric), a documented professional service history helps if you ever need to claim, and some brands explicitly require reasonable maintenance. Check your model’s paperwork for the specific clause.
Cleaning is on you. The rest is on us.
A monthly filter rinse is the single best thing you can do for your aircon. If you’d rather have the coil, drains, blower, refrigerant and electricals done properly before summer, book a pre-summer maintenance service. Brisbane, North Lakes, Aspley, Carindale, Mango Hill, Griffin, Deception Bay, Narangba, Burpengary, Redcliffe, Warner, Kawana, Caloundra, Buderim, Maroochydore, Coolum, Nambour, Palmview, and Gympie.
If it’s time to replace, request a free split or ducted quote, or visit our North Lakes, Kawana or Deception Bay showroom. Companion piece: How to Troubleshoot an Aircon That’s Not Cooling.
About the author
Steve is co-founder of AC Store and has spent 15+ years installing and servicing air conditioning across Brisbane, Moreton Bay, and the Sunshine Coast. AC Store: LG National Dealer of the Year 2024–2025, 10,000+ SEQ installs, 400+ verified 5-star reviews (4.9★), three locations. North Lakes and Kawana showrooms plus the Deception Bay warehouse. More about the team.
Published: mid-September 2026 | Last updated: 25 August 2026 | Next scheduled refresh: April 2027