5 Signs Your Air Con Needs Servicing Right Now

Your air conditioner works hard — especially through a Wollongong summer. Like any machine, it gives you warning signs before it breaks down completely. The problem is, most homeowners ignore these signs until the unit stops working entirely, turning what could have been a $180 service call into a $900 repair.

Here are the five most common signs we see across Illawarra homes that tell us a system needs professional attention — and why catching them early saves you money.

1. Warm or Weak Airflow

If your air con is running but the air coming out feels warm or the airflow seems weaker than usual, something is wrong. The most common causes are low refrigerant (gas), a dirty filter blocking airflow, a failing compressor, or ice build-up on the evaporator coil.

A simple filter clean can sometimes fix this immediately. But if that doesn't help, it's likely a refrigerant issue or a component starting to fail. Either way, don't run the system hard in this state — you risk burning out the compressor, which is one of the most expensive parts to replace.

2. Strange Noises — Rattling, Grinding or Squealing

A healthy air conditioner runs quietly. If you start hearing rattling, grinding, clicking, squealing or banging, your system is trying to tell you something is loose, worn out or broken inside.

• Rattling — loose panels, screws or debris caught in the fan
• Grinding — worn motor bearings (act fast, this gets expensive quickly)
• Squealing — belt slipping or motor bearings failing
• Clicking on startup — normal, but continuous clicking means a control problem
• Banging or clanking — a loose or broken fan blade hitting the housing

Turn the unit off if you hear grinding or banging. Running it further can cause irreversible damage to the motor or fan assembly.

3. Bad Smells — Musty, Burning or Chemical

Odours coming from your air con are always a red flag. The type of smell tells you what the problem is:

• Musty or mouldy smell — mould growing inside the unit or ducts (common in humid Illawarra summers)
• Burning or electrical smell — overheating wiring or motor (turn the unit off immediately)
• Sweet or chemical smell — refrigerant leak (harmful to breathe, call us straight away)
• Rotten egg or sulphur smell — could indicate a gas issue nearby, not the AC itself

4. Water Leaking Around the Indoor Unit

A small amount of condensation is normal. But if you're seeing water dripping from the indoor unit, pooling on the floor below it, or water stains on the wall, the drainage system is blocked or the unit is icing up.

Left unattended, water leaks cause mould growth in the wall cavity and ceiling damage — which is far more expensive to fix than the original air con problem. We see this a lot in older Wollongong and Shellharbour homes where the drain lines haven't been cleared in years.

5. Significantly Higher Power Bills

If your electricity bill has jumped but you haven't changed your usage habits, your air con may be working harder than it should to achieve the same result. A dirty coil, low refrigerant or failing components all reduce efficiency — the system uses more electricity to do less work.

An annual service typically restores efficiency to near-original levels and pays for itself within one or two electricity billing cycles.

How Often Should You Service Your Air Con?

For most Illawarra homes, an annual service before summer (September–October) is the sweet spot. If you run your system year-round or have a large ducted system, twice a year is worth it. See our full guide on service frequency for more detail.