Wet Season Prep: Getting Your Air Conditioner Ready in Cairns

The wet season in Far North Queensland runs roughly from November through to April. That is the stretch where your air conditioner stops being a nice-to-have and starts doing real work, all day and most nights. It is also the stretch where the units nobody has looked at in a few years quietly give up.

September and October are the sensible months to sort it. The build-up has not properly arrived, the diary is not full of breakdowns, and anything that needs a part can be ordered without you sweating through the wait.

What the tropics actually do to an air conditioner

An air conditioner does two jobs at once: it moves heat out of the room, and it pulls moisture out of the air. In Cairns the second job is the heavy one. Every hour the unit runs it is condensing water out of humid air, and that water has to get out of the house through a drain line that is usually a thin pipe running through a wall.

That constant moisture is also why coils here load up faster than they do down south. Dust and lint stick to a wet surface. Once a coil is coated, air stops moving through it properly, the unit runs longer to reach the same temperature, and it costs more to do it. Left long enough it becomes the damp, musty smell people notice the first time they switch the aircon on after a break.

On the coast there is salt on top of all that. Anywhere along the beaches, from Machans Beach and Holloways Beach up through Trinity Beach to Palm Cove, outdoor units sit in salt-laden air year round. Salt attacks the aluminium fins and the metal cabinet of the outdoor unit, and a corroded coil sheds performance long before it fails outright.

The jobs worth doing before November

• Pull the filters out and look at them. Most split systems have two filters that lift straight out of the indoor unit. If they are grey and furry, wash them, dry them fully, and put them back. Do it monthly through the wet.
• Get the coils cleaned properly. Filters catch some of it, not all of it. The coil behind them is where the real build-up sits, and it needs a proper chemical clean rather than a spray and a wipe.
• Check the drain is actually draining. Find the outlet outside and make sure water runs out of it while the unit is going. A blocked drain in the wet season is how you end up with water tracking down an internal wall.
• Clear the outdoor unit. Cut back anything growing over it, pull the leaves out of the fins, and give it room to breathe. If you are near the beach, a hose down with fresh water helps get salt off the fins.
• Run it before you need it. Switch it on for an hour on a warm afternoon in September. If it is going to disappoint you, better it does that now than at nine at night in February with a storm sitting over the house.

What you can do yourself, and what you cannot

Filters, clearing space around the outdoor unit, and keeping the drain outlet clear are all homeowner jobs. Nothing there needs a licence and doing them makes a genuine difference.

Anything involving refrigerant gas is different. In Australia it is against the law for an unlicensed person to handle refrigerant, and the electrical side of an installation is licensed work too. That is not an upsell, it is the rule. FNQ Air Solutions Pty Ltd holds QBCC licence 15533799 and ARCTick refrigerant handling licence AU62644, and both are checkable on the public registers.

How often a system needs servicing up here

Manufacturer service schedules are written for a national market, which in practice means a milder climate than this one. Our view, from what we pull out of local machines, is that a domestic split system in Far North Queensland is worth a service once a year, done before the wet rather than during it. Units on the beaches, units that run most of the day, and anything in a dusty spot are worth looking at more often than that.

Commercial refrigeration sits on a different schedule again. Most coolrooms, freezers and display cabinets get serviced at least twice a year, and busy kitchens more often, because the cost of a failure is a whole load of stock rather than an uncomfortable night.

Signs a system will not make it through the wet

• It takes noticeably longer to cool the room than it used to.
• A musty or sour smell in the first few minutes after start-up.
• Water dripping or staining the wall under the indoor unit.
• Ice forming on the pipework or on the face of the indoor coil.
• It trips the breaker, or it runs and then shuts itself down.
• It has got louder, or it rattles in a way it did not last year.

Any one of those is worth a look. Several of them together usually means the unit has been struggling for a while and the wet season is going to finish the job.

Getting it sorted

We service air conditioning and refrigeration across Cairns and the inner suburbs, Stratford, Freshwater, Redlynch and Brinsmead, the full beaches corridor from Machans Beach to Palm Cove, south through Edmonton and Gordonvale, and up the Range to Mareeba and Atherton. Tell us the suburb and what the system is doing and we will tell you what it needs.