How Often Should You Actually Service an Air Conditioner in Darwin?

Short answer: at least once every two years, and preferably once a year. Do not leave it five. Here is why that is different to what you would be told down south.

Why Darwin is not like anywhere else

Most servicing advice you will read online was written for a climate where the air conditioner runs three or four months a year and the air is dry. Ours run for eight months, sometimes more, in humidity that sits high for half the year.

That combination does two things. It puts far more running hours on the unit, and it turns the inside of your indoor unit into somewhere mould is very happy to live. A split system in Darwin builds up in one year what a Melbourne unit might take three to accumulate.

What actually happens when you leave it

People tend to think of servicing as optional maintenance, like a car service you can push back a few months. What is really happening is a slow build-up on the barrel fan and the indoor coil.

• The smell. That musty hit when it first starts is mould and bacteria on the fan and coil. It is the most common reason people finally ring us.
• It stops cooling properly. A coil packed with dust cannot transfer heat, and a filthy barrel fan cannot move air. The unit runs longer and longer to do less and less.
• Your power bill climbs. Quietly, over a couple of years, so most people never connect the two.
• Water starts appearing. A dirty coil and a blocked drain is how condensate ends up running down an internal wall instead of outside.

So how often, really?

Every two years is the minimum. Annually is better, and for some houses it should be more often than that.

Go annual, or closer, if any of these apply:

• The unit is in a bedroom and runs most nights
• Anyone in the house has asthma, allergies or hayfever
• You have pets
• You are on the coastal side and getting salt air on the outdoor unit
• The system runs close to year round rather than seasonally

What a proper service actually involves

This matters, because “servicing” covers a lot of ground and some of it is barely worth paying for. Pulling the filters out and hosing them off is not a service. The mould and grime that cause the smell live behind the filters, on the barrel fan and the coil, where a quick clean never reaches.

A proper job means the filters, the barrel fan, the indoor coil, the vanes and the housing all cleaned and sanitised. The drain flushed. The outdoor unit cleared. And because we hold the electrical licence as well as refrigeration, the electrical connections and the refrigerant performance get checked while we are there.

When to book it

Before the build-up, not during it. Late in the dry is ideal — the system gets sorted before you need it, and you are not waiting behind everyone who left it until the first 35 degree week.

If you cannot remember the last time yours was done, it is due. If you have just bought the house and have no idea of the history, treat it as never done.