Getting Your Aircon Ready Before the Build-Up Hits

Every year the first properly hot week of the build-up fills our calendar in about three days. The units that die in that week are almost never a surprise — they were already struggling through the dry and nobody was asking much of them yet. Here is what to check yourself this weekend, what a proper clean actually reaches, and what it costs.

What the build-up actually does to an air conditioner

Through the dry, most units in Darwin are doing part-time work. The nights are cool enough to sleep without them, the air is dry, and a machine that is only half healthy still gets the room down. Nobody notices anything is wrong.

Then the build-up arrives and the job changes completely. The temperature climbs, the humidity climbs with it, and a unit that was running a few hours a day starts running most of the day and all night. A machine coping at half load fails at full load. That is the whole reason breakdowns arrive in a cluster rather than spread through the year.

Two things get worse at the same time. The coil now runs cold and wet for far longer each day, which is exactly what the mould on it has been waiting for. And the condensate drain that has been handling a trickle suddenly has to carry litres a day — so a partial blockage that caused no trouble in July starts running down the inside of your wall in October.

The five-minute check worth doing this weekend

You do not need us for this part. Do it now, while there is still time to book if something turns up.

• Pull the filters out and hold them up to the light. If light does not come through them, they have been choking the unit for the whole dry season. Rinse them, dry them properly, put them back.
• Shine a torch past the vanes into the barrel fan. That is the long cylinder behind the coil. Black speckling on the blades means mould, and what you can see is the good half — the back of the fan is always worse.
• Go and look at the outdoor unit. Clear the leaves and grass clippings off the fins, and give it clear air on all sides. If it is boxed in behind a fence or buried in a garden bed, it is trying to dump heat into air that is already hot.
• Run it on cooling at 18 degrees for fifteen minutes, then hold your hand at the outlet. It should be cold, not cool. If it is only cool, write down the date — that is a real symptom and it will not fix itself.
• Look at the wall directly under the indoor unit. Any staining, any bubbling paint, any watermark. That is the drain telling you about October in advance.

If all five come back clean and the unit was serviced within the last twelve months, you are probably fine until Christmas. We would rather tell you that than sell you a service you do not need.

What rinsing the filters does not reach

The filters sit in front of everything that actually causes the problem. Rinsing them is worth doing and you should — but it does not touch the coil or the barrel fan, and that is where the mould, the smell and the lost airflow live.

A proper clean means the unit comes apart. The barrel fan comes out and gets washed, the coil gets chemically cleaned front and back, the drain gets flushed and checked that it actually flows, and the casing and vanes get done properly rather than wiped. On the outdoor side the fins get cleaned and the unit gets checked over while we are there.

It takes us under an hour a unit, and it is the difference between a unit that smells better for a fortnight and one that works properly for a season.

The three things that cost real money if you leave them

• A blocked drain. The cheapest problem on this list to fix and the most expensive to ignore. Water comes out the front of the unit and goes into the gyprock.
• A dirty coil. The unit cannot move heat through a layer of grime, so it runs longer and harder to get the same room temperature. You pay for that twice — once on the power bill and once in wear on the compressor.
• The timing. This is the one that actually hurts. A unit that fails in the first 35 degree week fails at the same moment as everyone else’s, when every aircon company in Darwin is booked out and nobody can get to you quickly.

How often, honestly

Air conditioners need servicing at least once every two years, and once a year is better. Do not leave it for five.

Most of what you will read online was written for a climate where a unit runs three or four months a year in dry air. Ours run eight months, often closer to twelve, in humidity that sits high for half the year. A split system in a Darwin bedroom builds up in one year roughly what a Melbourne unit takes three to accumulate. The southern advice does not transfer, and following it is how units end up in the state we find them in.

If you have just bought the house and have no idea of the history, treat it as never done.

What it costs

One unit is $231, everything included. There is nothing added on top of that — no call-out line, no travel, no disposal fee at the end.

Where it gets interesting is more than one:

• Two units — $388.85. That is $194.43 each.
• Three units — $546.70. $182.23 each.
• Four units — $704.55. $176.14 each.

The reason the per-unit price falls is simple: a good part of what any single visit costs is getting a licensed technician, the gear and the chemicals to your house. Once we are there, the next unit is mostly just time — we allow under an hour each. Doing four in the one visit takes $54.86 off every unit against booking them one at a time across four years, and they then age together, which makes every service after this one simpler.

We are a Fujitsu Authorised Service Partner, and we work on every brand.

When to book it

Now. Not because we want the work in the diary — although we do — but because the calendar genuinely closes. From about the middle of September the phone changes character, and by the first hot week we are booking a fortnight out. Everyone who rings us in that fortnight had the same three weeks in August that you have right now.

Book it in the dry and you choose the week. Book it in the build-up and you take what is left.