Air Conditioner Leaking Water in Cairns
Water down the wall is almost always condensate that has lost its way out of the building.
- Drain cleared and flow tested
- Fall and drain line checked, not just flushed
- Barrel fan and coil mould addressed
- Iced coil ruled in or out
Where the water is coming from
An indoor head is a dehumidifier as much as a cooler. Warm wet air passes over a cold evaporator coil, moisture condenses out of it, runs down the fins into a drain tray and leaves the building through a drain line. In a Cairns wet season a hard working split system can pull litres of water out of a room in a day. That is normal, and none of it should ever appear inside.
When it does appear inside, dripping from the bottom edge of the head, running down the wall behind it, or staining the plasterboard, the condensate has not made it to the drain. Almost always the drain is blocked, the tray is overflowing, or the water is being flung off a coil it should not be sitting on.
Why drains block so readily here
Condensate volumes in this climate are high and the water is not clean. It carries dust, salt and whatever the filter did not catch. Add the humidity and you get biological growth in the tray and the drain line within a season, the slime that eventually plugs the outlet. Mould that grows across the evaporator and through the barrel fan sheds into the same tray. In older installs the drain also picks up insects, geckos and nests at the discharge end.
Then there is fall. A condensate line is gravity fed and needs continuous fall the whole way out. Drain lines that were run flat, sagged over a ceiling batten, looped up over a stud or connected with a kink hold water permanently, and standing water in a warm humid ceiling space blocks fast. That is an install fault rather than a maintenance fault, and flushing it only buys a few months.
What the repair involves
The drain gets cleared and the flow tested with water, not declared clear because air passes. The tray comes out where the head allows it and gets cleaned properly. Blocked drains and mould travel together up here, so the barrel fan and coil usually need attention at the same time, otherwise the growth simply sheds back into the tray. Where the line has no fall, the fix is re-running or re-supporting it rather than flushing something that will block again by Christmas.
Not every leak is a drain. A coil that has iced over, from a blocked filter, failed fan or low refrigerant charge, dumps a lot of water at once when it thaws, and that presents as a leak while the actual fault is elsewhere. So does a head that was hung slightly out of level at install, which sends condensate to the wrong end of the tray. Both get ruled in or out on site.
When it is not worth repairing
A cracked or corroded drain tray on an older unit is often not economically replaceable, because the part cost and the labour to strip the head down approach the value of the machine. Same story if the leak turns out to be a corroded evaporator that has been weeping for a while. We will tell you when that is the case.
Water running into plasterboard or across a switchboard is worth dealing with promptly, not after the wet. Call 0489 266 523 to get it looked at.
Where we work
- Babinda The wettest town in the country, where drainage and outdoor unit siting decide how long a system lasts.
- Bentley Park Small blocks and close-set houses, where the outdoor unit location decides the whole system design.
- Edge Hill Heritage Queenslanders with no wall cavity, where the pipe route is the hardest part of the job.
- Edmonton Southern corridor estates where most installs go into new slab-on-ground homes within months of handover.
- Innisfail Rebuild-era housing where the mounting standard is the whole conversation, and rainfall does the rest.
- Gordonvale Cane country, where the thing that quietly costs a system its capacity is what settles on the coil.
- Mission Beach Salt and cyclone exposure together, on properties that often sit empty between guests.
- Redlynch A valley suburb where humidity sits higher than the coast, so sizing for moisture removal matters more than raw output.
- Smithfield Heavy rental turnover near JCU, where reliability between tenants matters as much as the install itself.
- Trinity Beach Direct salt exposure off the water, where coil specification and condenser siting decide how long a system lasts.
- Tully Rainfall and humidity at the extreme end, on blocks where the supply run is often the real constraint.
Tell us what it is doing
Describe the symptom and the unit and you will get an idea of what is going on before anyone comes out.
- Hours
- Weekdays 7 until 5, Saturday mornings
- Area
- Cairns, the beaches, and south to the Cassowary Coast
- Quotes
- In writing, itemised, no obligation
- We ask what the rooms are doing before we quote a size, not after.
- The quote covers the mount, the line set, the electrical and the make good, so there are no line items appearing on install day.
- Written, itemised, and yours to compare against anyone else's.