Signs Your Air Conditioner Needs Repair

Failures rarely arrive without notice

Almost nothing in a split system breaks instantly. Bearings get louder, a capacitor weakens before it fails, a leak drops the charge slowly, a coil chokes up gradually. What people experience as a sudden breakdown in the middle of January is usually a fault that has been signalling for months on a machine nobody was listening to.

The reason that matters financially is that most of these faults are cheap while they are still symptoms and expensive once they take something else with them.

Three of those have enough behind them to be worth reading on their own. If the unit runs but the air is not cold, start with an air conditioner that is not cooling, which is a different diagnosis from a unit that will not start at all. If there is water inside, that is an air conditioner leaking water and it is nearly always the drain rather than the refrigeration circuit. And if it is the middle of February and the house is unlivable, we do emergency air conditioning repair rather than putting you in a queue.

Noises and smells

A hum or a click at start up followed by the compressor not running, especially in the heat of the afternoon, points at a capacitor or contactor. Both are small parts. Both leave the compressor drawing locked rotor current while it fails to start, which is not something to keep trying.

A rising grinding or squealing from the outdoor unit is usually a fan motor bearing. A rattle that comes and goes with fan speed is often a loose panel or a bracket working itself loose, which in this region is worth checking properly rather than ignoring.

A musty smell on start up is biological growth on the coil and blower and calls for a clean, not a repair. A sharp chemical or acidic smell is different, and a burning or electrical smell means switch it off at the isolator and call somebody.

Ice, weak airflow, water and drifting bills

Ice on the indoor coil or frost on the copper suction line at the outdoor unit is the one to act on quickly. It means either airflow is restricted, from a blocked filter or a fouled coil, or the refrigerant charge is low. Both cause the coil to run below freezing, and ice then blocks airflow further and makes it worse. Running a system in that state lets liquid refrigerant return to the compressor, and a compressor is designed to compress gas, not liquid. That is exactly how a filter problem or a small leak becomes a compressor replacement.

Weak airflow with no ice is usually filters, a dirty blower wheel or a partly crushed duct. Water dripping inside from the indoor unit is normally a blocked condensate drain, and in the wet season that is one of the most common calls there is.

Then there is the slow one. A unit that used to hold the lounge room comfortable and now runs constantly to do the same job has lost capacity somewhere. The bill usually notices before the occupants do.

The ones that mean stop using it now

Turn it off at the isolator and get it looked at rather than persisting if:

• The breaker or RCD trips when the system starts
• There is any burning smell, or visible scorching at the isolator or the board
• The outdoor unit is running with ice on the pipework
• The compressor is trying to start repeatedly and failing
• Water is running down the wall from the indoor unit

The safe checks you can do yourself are short:

1. Confirm the mode and the set point, since a unit left in fan or dry mode is the single most common call out that turns out to be nothing
2. Wash the filters and let them dry properly before refitting
3. Check the outdoor unit is not blocked by vegetation, bins or stored boxes
4. Check the isolator switch beside the outdoor unit is on
5. Check nothing else on that circuit has tripped at the board

Anything past that involves refrigerant or mains wiring and legally needs a licensed technician.

If any of the above sounds like your unit, see air conditioning repairs in Cairns or call 0489 266 523.