Air conditioning breakdown in a heatwave: what to do before the technician arrives

This is general safety information, not medical advice. If someone is showing signs of heat-related illness, confusion, dizziness, or feeling unwell, seek medical help rather than waiting for the air conditioning to be fixed.

A breakdown during a heatwave is one of the more stressful moments in owning an air conditioner, mostly because it tends to happen exactly when you need the system most. A few quick checks and some sensible steps while you wait can make a real difference to how the next few hours go.

Quick checks before you call anyone

Not every “the aircon’s dead” moment is actually a major fault. A few things are worth ruling out first:

• Check the circuit breaker or isolator switch. A tripped breaker is a common and simple cause of a system that suddenly stops responding.
• Check the remote. Flat batteries or an accidentally changed setting cause more no-cooling calls than people expect.
• Look at the filter. A severely blocked filter can restrict airflow badly enough that the system seems to have stopped cooling properly, even though it’s technically running.
• Listen for anything unusual. A grinding, clicking or buzzing sound is worth mentioning to whoever you call, since it helps them understand what might be wrong before they arrive.

If none of that resolves it, the system genuinely needs a technician, and refrigerant or electrical faults aren’t something to attempt yourself, even under pressure to get cooling back fast.

Staying safe while you wait

Extreme heat is genuinely dangerous, not just uncomfortable, so treating the wait time seriously matters. Move to the coolest room in the home, typically one without direct sun and away from appliances that generate heat. Use fans to keep air moving even without cooling, since airflow alone helps the body regulate temperature. Keep drinking water regularly rather than waiting until you feel thirsty, and if the heat is severe and the wait for a repair looks long, a few hours somewhere air-conditioned, a shopping centre, library or a friend’s place, is a reasonable and sensible option rather than toughing it out at home.

Situation	What to do
System won’t turn on at all	Check breaker, isolator switch, remote batteries
Running but not cooling	Check filter, listen for unusual sounds, note them for the technician
Wait for repair looks long	Move to coolest room, use fans, stay hydrated
Household includes infants, elderly or unwell people	Prioritise getting them to a cool space over waiting it out

Who’s most at risk

Heat affects people differently, and a breakdown during a heatwave carries more risk for some households than others. Infants, older adults, pregnant women, and anyone managing an existing health condition are more vulnerable to heat stress and should be prioritised for a cool environment, even if that means a short trip elsewhere rather than waiting at home for a repair. If anyone shows signs of confusion, dizziness or feeling unusually unwell, treat it as urgent and seek medical help rather than waiting to see if it passes.

Getting the repair sorted

Once you’re safely managing the immediate heat, the practical next step is booking a repair. Our 24/7 emergency callout hub lists Perth contractors who handle urgent breakdown calls, so you can compare who’s available quickly rather than searching from scratch mid-heatwave.

What to have ready when you call

Having a few details ready before you dial speeds things up considerably: the system’s brand and rough age if you know it, what exactly is happening (no power, running but not cooling, a specific noise), and whether you’ve already tried the basic checks above. Mentioning that it’s a heatwave and describing anyone vulnerable in the household, an infant, an older person, or someone with a health condition, can also help a contractor prioritise the callout appropriately.

Preventing the same thing next time

Once the immediate breakdown is sorted, ask the technician what caused it and whether it’s the kind of fault a pre-season check would have caught. A surprising number of mid-summer breakdowns trace back to something that would have shown up in a routine service months earlier, a blocked filter restricting airflow, a slow refrigerant leak, or a condensate drain that had been building toward a blockage. Booking a check before next summer starts is a far more comfortable way to find that kind of issue than discovering it during the next heatwave.

For more on how we rank and assess contractors, see our methodology page. Visit the home page for other guides on servicing and keeping a system reliable through summer.