Every spring, thousands of Australian households walk out to the controller, press “cool” for the first time since autumn, and hold their breath. What comes out of the vents in the next two minutes decides whether the summer starts comfortably or with a frantic search for a technician on the first 38-degree day.
The good news is that an evaporative cooler is a simple machine, and it tells you what it needs if you know how to listen. Most start-of-season problems fall into one of two buckets: the unit is fine but overdue for a service, or something has actually broken and needs a repair. Fifteen minutes with the controller, a torch and your own ears will usually tell you which. Here is how to run that check, what each result means, and when to stop and call someone.
Step 1: Power up and listen (two minutes)
Switch the unit to fan-only first, not cool. You should hear the fan spin up smoothly within a few seconds and feel steady airflow at the nearest vent.
- Smooth fan, good airflow: the mechanical side is healthy. Move to step 2.
- A hum but no airflow: stop. A motor that hums without turning is usually a failed capacitor or a seized bearing, and running it will burn the motor out. This is a repair, not a service.
- Squealing or grinding: a belt or bearing problem. Switch it off. Caught now it is a small repair; left for a month it becomes a motor replacement.
- Nothing at all: check the wall isolator (often in the roof space or laundry) and the circuit breaker before you assume the worst. A tripped breaker after winter storms is the single most common “dead cooler” call.
Step 2: Switch to cool and wait for the water (three minutes)
Now select cool. Most units pre-wet the pads for a minute or two before the fan ramps up, so a short pause is normal. Then put your hand at a vent.
- Air turns noticeably cooler and slightly humid: water is reaching the pads and evaporating. Good.
- Air stays warm after five minutes: water is not getting to the pads. That is either a dry reservoir, a stuck float valve, a pump that has not primed, or pads so choked with scale that water runs off them. Sometimes a service fixes it; if the pump has failed, it is a repair.
- A musty or “wet cardboard” smell: almost always stagnant water and biofilm left in the tray over winter. Unpleasant but usually a service job, because the fix is a proper clean and descale rather than a new part.
Step 3: Look at the roof and the ceiling (five minutes)
You do not need to climb up. Stand back from the house and look at the unit, then walk inside and look at the ceiling below it.
- Water running down the roof or sheeting: the float or drain valve is overfilling the tray. Turn the unit off. Left running it can rot roof timbers and stain ceilings.
- Damp patches on the ceiling: the same problem, further along. This is urgent and it is a repair.
- Visible sag, gaps or white crust on the pads: scale and worn pads. A service will clean or replace them, and it is worth doing before the pads get bad enough to let hot air bypass them entirely.
Step 4: Check the controller and the water bill (five minutes)
Modern controllers show fault codes; older ones show a blank screen or refuse to respond. A blank screen with power to the unit points to a controller or wiring fault, which is a repair. And if last summer’s water bill jumped without an obvious reason, a leaking or overfilling cooler is a common culprit worth mentioning to whoever inspects it.
So which is it?
Roughly speaking, if the unit runs and cools but smells, cools weakly, or simply has not been touched in a year, you need an evaporative cooler service: tray cleaned and descaled, pads checked or replaced, water level and float set, pump and distribution tested, electrics and controller checked. Booking a professional evaporative cooler service in Perth in spring, before the heat, is the cheapest insurance an owner can buy, because everything above that is “usually a service” turns into a repair if it is ignored for another season.
If the unit hums without spinning, bangs, trips the breaker, leaks onto the roof or ceiling, or will not respond at all, you are past servicing and into evaporative air conditioner repairs. Switch it off, do not keep restarting it, and get a technician to it before the first hot week when every repairer in the city is booked solid.
The mistake to avoid
The most expensive thing an owner can do is neither of the above: keep running a struggling cooler through November because it is “sort of working”. A pump straining against scale, a motor with a failing bearing or a tray quietly overflowing onto the roof will all get worse under load, and the bill goes from a service to a repair to a replacement in a single season.
Why the timing matters in Perth
Perth’s hard scheme water and long dry summers make it one of the best places in the country to own an evaporative cooler and one of the harshest on the machine itself. Scale builds faster, units run longer, and the whole city switches on within the same fortnight. Doing the fifteen-minute check in September, and booking whatever it points to in October, is the difference between a quiet summer and a very long queue.
*Provista Plumbing & Gas services and repairs evaporative cooling systems of all major brands across the Perth metro area.*
