If your aircon is dripping water inside, stop running it and check the drain first
Water from the outside drain is normal. Water from the indoor head, ceiling cassette, return-air grille or wall is not. Most Sunshine Coast aircon water leaks are blocked drains, dirty filters or iced coils, usually $180 to $850 to fix before ceiling damage starts.
Urgency triage: what the water leak usually means
| Symptom | Likely cause | How urgent | Likely repair cost |
|---|---|---|---|
| Water dripping outside from a small drain pipe | Normal condensate drain in cooling mode | No trade needed | $0 |
| Indoor head drips after 20 to 40 minutes | Blocked drain line, dirty tray or poor fall | Same week | $180 - $450 |
| Water runs down wall from split system | Blocked drain, cracked tray or unit out of level | Same week, sooner if near power | $220 - $650 |
| Ice on indoor coil, then water when it melts | Dirty filter, airflow restriction or low refrigerant | Same week in summer | $180 - $1,200 |
| Ducted return-air grille has water marks | Blocked drain, failed pump or sweating ductwork | Same week | $260 - $950 |
| Ceiling stain near ducted unit | Overflow tray, drain safety fault or roof-space condensation | Urgent before more ceiling damage | $350 - $1,450 |
| Safety switch trips when aircon runs | Water near electrical parts or electrical fault | Stop using and book urgently | $250 - $1,500 |
This table covers common residential split and ducted faults. For poor cooling without water, use the aircon won’t cool guide.
What you can safely do yourself
First, turn the system off if water is coming inside the room or ceiling. Put a towel or tray under the drip, but do not keep running the unit to "see if it clears". Air conditioners pull litres of moisture out of Sunshine Coast air on humid days, so a blocked drain can wet plaster fast.
Clean the return-air filter. A clogged filter reduces airflow, which can make the indoor coil too cold. The coil ices up, then melts and overflows. For a split system, lift the front cover and wash the filters with water, then let them dry before refitting. For ducted, remove and clean the return-air grille filter if you can reach it safely from a ladder.
Check the outdoor drain outlet. It might be a small pipe ending near a garden bed, downpipe or outside wall. Mud, insects, mulch and algae can block the end. You can clear the end gently, but do not push wire up the line toward the indoor coil. That can puncture drain tubing or push the blockage deeper.
Set the thermostat sensibly. Running at 18°C all day in humid weather can make an already dirty unit ice faster. A test at 24°C with clean filters is fair. If it still drips, book a technician.
Do not remove covers around electrical terminals, do not handle refrigerant pipework, and do not pour harsh chemicals into the drain. If a safety switch trips twice, leave it off. Queensland electrical safety guidance is clear that hard-wired air conditioning equipment belongs with licensed electrical workers.
Water inside the house?
Send a photo of the leak point, the controller and the outdoor unit. We will tell you whether it looks like a drain, airflow or refrigeration fault.
What can wait, and what should not
If the only water you see is outside at the drain outlet, you do not need to pay a tradesperson. That is the system removing humidity from indoor air. You may notice more water on muggy days in Maroochydore, Mooloolaba and Caloundra because the air carries more moisture.
A small drip from the indoor head that stops after filter cleaning can wait if it does not return. Book an annual service before next summer, because a dirty coil and tray will usually block again. If the leak returns the same day, it is not solved.
Same-week jobs are leaks from the indoor head, water stains around a ducted return-air grille, musty smells with water marks, or ice forming on copper pipes. These often start as $180 to $650 repairs. Leave them until peak summer and they can become damaged plaster, wet insulation, stained paint and emergency call-out rates.
Urgent jobs are water near a light, fan, smoke alarm, switch, powerpoint or switchboard. Turn the system off and book help. If stormwater has entered the outdoor unit after wild weather, do not restart it until checked. The Sunshine Coast gets summer storms, salt air and high humidity, and those three conditions punish electrical components.
Typical repair paths and what they cost
A straightforward split-system drain clean is the cheapest path. The technician removes the cover, clears the drain, cleans the tray and tests fall. Expect $180 to $450. If the indoor head was installed without enough fall toward the drain, the proper fix may need the unit re-levelled or the drain rerouted.
A condensate pump fault is more expensive because the pump, float switch and discharge line have to be tested. This is common where the aircon cannot drain by gravity, such as internal walls, units and some commercial tenancies. Allow $350 to $850 depending on pump type and access. For commercial spaces, the commercial aircon page explains why maintenance contracts often include drain checks before summer.
If ice is involved, do not assume it is only a drain problem. A dirty filter can be free to fix. A blocked coil clean may be $180 to $420. A refrigerant leak investigation can move the job to $450 to $1,200 because licensed refrigerant handling, leak testing, repair and recharge are involved. See the service page for what a proper clean covers.
Ducted systems add roof-space variables. A failed pump, blocked safety tray, sweating duct or sagging flexible duct can all show as a water stain. A $260 diagnosis is worthwhile before cutting plaster. If the system is older and also cooling poorly, compare the repair against ducted repair cost ranges before approving major parts.
Get your leaking aircon checked
Send photos of the drip point and the system brand and we will reply within 1 business day with the likely next step.