00
Tell us what you smell
Musty, sewage, burning or chemical. What you tell us on the phone points us at the fault before we even arrive.
We find what's causing the stink and fix it properly. Sydney wide, since 1991.
Air Conditioner Smells Bad?
Common AC Problems
Why Your Air Conditioner
Smells Bad
A musty dirty-sock smell from your air con is mould in the coil or the drain. A burning smell is electrical, switch it off now. A sewage smell is a drain problem. A chemical smell can be a refrigerant leak. That covers nearly every smelly air con we walk into.
When an air conditioner smells bad, the type of smell tells you the fault. Some of it you can sort yourself in ten minutes. The rest needs a proper clean or a repair, and we do both.
We've been chasing down air con smells across Sydney since 1991. The fix is usually cheaper than people expect. A blocked drain clear is $120 to $150. A proper chemical coil clean runs $200 to $300, and that kills the mould rather than masking it. A standard service call to find the fault is $250 plus GST, and we quote any repair before we start. See our pricing page for the full rundown.
Don't bother with supermarket deodoriser sprays. They mask the smell for a day and the mould keeps growing. Get the cause sorted once and it stays gone. 4.8 stars from 280+ reviews says we're doing something right.
0+
Years of Industry Experience
Licensed, Certified & Insured Technicians
Environmentally Responsible & ARCtick Certified
100% Service Satisfaction Guarantee
Flexible & Affordable Financing Options
Wide Range of Systems & Leading Brands
Quick Checks First
Before You Call About the Smell
Four Free Checks First
Run fan mode only
Switch it to Fan for half an hour with the windows open. If the smell fades, it's moisture sitting in the unit between runs. If it comes straight back on Cool, there's mould or a drain issue that needs a proper clean.
Check the filter
Pop the front cover and pull the filters out. If they're grey and furry, give them a wash under the tap and let them dry before they go back. A filthy filter holds damp dust, and damp dust stinks.
Look for water or slime
Have a look in the bottom of the indoor unit and around the drain outlet outside. Standing water or grey slime means the drain's blocked, and stale water smells exactly how you'd expect.
Notice what kind of smell it is
Musty means mould. Sewage means drain. Burning means electrical, so switch it off at the breaker straight away. Chemical means a possible gas leak. Telling us which one saves diagnosis time when you call.
If the Smell Is Still There
If you've washed the filters and run fan mode and the smell keeps coming back, the problem is deeper in the unit. Nine times out of ten it's the indoor coil. The coil sits wet all summer, dust sticks to it, and mould grows through the fins where you can't see it. Every time the fan kicks on, it blows air across that mould and into your room. That's the dirty-sock smell, and no spray can fixes it.
The proper fix is a chemical coil clean. We pull the unit down, foam the coil with a cleaner that kills the mould, rinse it through and clear the drain while we're in there. It runs $200 to $300 depending on the unit, and the difference is immediate. If your air conditioning smells bad every time it starts up, this is almost always the job that sorts it. And if your air conditioner smells musty only when it first kicks on, same story, the coil is the source.
Sewage or damp smells are a different animal. That's the condensate drain, either blocked and holding stale water or, in some setups, a dried-out trap letting drain smells back up. A drain clear is $120 to $150 and we usually do it on the spot. If you're also seeing water dripping from the unit, the two go together, have a read of our leaking water page.
Burning or chemical smells are the ones we treat as urgent. Burning means an electrical fault or a motor cooking itself. A chemical or nail-polish smell can mean refrigerant leaking out. Both mean switch it off and give us a bell on (02) 9820 4500.
We do this on every brand and every type of system, splits and ducted both. More on those over at our split system repairs and ducted repairs pages.
Common Factors
Common Bad Aircon Smells
What Different Smells Can Mean
Different smells point to different faults. Here's what each one usually means and what it costs to sort. If yours doesn't fit any of these, ring us and describe it, we've heard them all.
Musty or mouldy smell
Mould or mildew growing on the indoor coil or in the drain pan. It gets blown into the room every time the fan starts. The fix is a chemical coil clean, $200 to $300, which kills the mould rather than covering it up.
Dirty or stale smell
Usually packed filters holding damp dust, sometimes years of grime through the indoor unit. Wash the filters yourself for free. If it needs a proper internal clean, a filter service starts at $150.
Sour or damp smell
Stale water sitting in the drain pan or a blocked condensate line. The water goes off and the smell follows. A drain clear is $120 to $150, usually done same visit.
Burning smell
Switch it off at the breaker now. Burning smells mean an electrical fault, a seized motor or wiring cooking itself. A failed fan motor runs $300 to $500 fitted. Don’t run it again until it’s been looked at.
When to Stop Using the System
Most smells are a nuisance, not a danger. Two are different. A burning or hot plastic smell means electrical trouble, switch the system off at the breaker and don't run it again until it's checked. A sharp chemical smell, especially with a hiss or weak cooling, can mean refrigerant escaping, same deal, off and call us. And if anyone in the house has asthma or allergies, don't keep running a mouldy unit, the spores go room to room. If it can't wait, we treat it as an emergency repair.
Diagnosis Process
How We Find the Smell
We don't guess and we don't sell you a clean you don't need. Here's how a smell job runs from the first call to fixed.
00
Inspect the indoor unit
Covers off, torch out. We check the coil, the fan barrel and the drain pan, which is where most smells live.
00
Check filters and airflow
Packed filters and a dirty fan barrel hold the smell even after a coil clean, so we check the lot, not just the obvious bit.
00
Test the drain
We run water through the condensate line and check it clears properly. Stale water in a blocked drain is a smell factory.
00
Quote, then fix
Once we know the cause you get a price before we start. Most cleans and drain clears are done the same visit.
Choose the Right Fix
Smell Jobs We've Done
Daikin split, dirty-sock smell – Cabramatta
5kW Daikin in a rental, musty blast every time it started. Coil was green through the fins. Chemical coil clean, drain flushed, filters washed. Smell gone that day. $280.
Ducted system, sewage smell in the hallway – Kellyville
Panasonic ducted, damp sour smell near the return air. Drain pan was holding a litre of stale water from a blocked condensate line. Cleared the line, sanitised the pan, retested the fall. $150.
Fujitsu split, burning smell – Engadine
Owner did the right thing and shut it off at the breaker. Indoor fan motor had seized and was cooking its windings. New motor fitted and tested. $380, and the unit lives on.
Sick of the Smell?
Give us a bell on (02) 9820 4500 and tell us what you're smelling. Family run since 1991, licensed (NSW 273312C), ARCtick certified (AU13058), 4.8 stars from 280+ reviews. Monday to Friday 7am-5pm, Saturdays by arrangement. We quote the fix before we start, and most smells are gone the same visit.
FAQ's
Smelly Air Con - Your Questions
Mould on the indoor coil or in the drain pan. The coil stays wet all summer and mould loves it. A chemical coil clean for $200 to $300 kills it properly. Sprays just mask it.
Work out which smell it is. Musty means mould, sewage means a drain problem, burning means switch it off at the breaker now, chemical can mean a gas leak. Wash your filters first, and if the smell stays, give us a bell on (02) 9820 4500.
Yeah, it’s the first thing to check. A packed filter holds damp dust that stinks when air moves through it. Wash it under the tap, dry it, put it back. Costs you nothing. If the smell hangs around, it’s the coil.
It’s not great. The fan blows mould spores into every room it cools, which is rough on anyone with asthma or allergies. A proper coil clean sorts the source, not just the smell.
Stale water. Either the condensate drain is blocked and the pan is holding old water, or drain smells are backing up the line. A drain clear is $120 to $150 and it’s usually fixed on the spot.
Treat it like it is. Switch the system off at the breaker and leave it off. It’s usually a motor or wiring fault, and running it makes it worse. Call us and we’ll get it looked at quick.
Yes. One mouldy coil at the unit feeds every vent in the house, so the whole place smells at once. The fix is the same as a split, clean the coil and the drain at the source.
Wash your filters every couple of months and get the system serviced once a year. Our service plans start at $150 and include the bits that stop mould getting started. Cheaper than another call-out.
Jay’s Air. Family run since 1991, our own blokes not subbies, fixed pricing and no surprises. Licensed (NSW 273312C), ARCtick certified (AU13058), 4.8 stars from 280+ reviews. Give us a bell on (02) 9820 4500.