If your air conditioner won’t turn on, start with these checks: look for a tripped circuit breaker at the switchboard, replace the remote batteries, and confirm the unit is set to the right mode. These fix the majority of “dead” air conditioners. If the breaker keeps tripping or there’s no power reaching the unit, it’s an electrical fault that needs a licensed electrician. Here’s how to troubleshoot it step by step.
Quick Checks (Do These First)
1. Check the Circuit Breaker
Go to your switchboard and look for a tripped breaker — one sitting in the middle or “off” position. Flip it fully off, then back on. If it trips again straight away, stop: that’s an electrical fault and needs a licensed electrician, not repeated resetting.
2. Replace the Remote Batteries
Dead remote batteries are one of the most common causes of an air conditioner that “won’t turn on”. Fit a fresh set, point the remote at the indoor unit, and make sure nothing is blocking the sensor.
3. Check the Isolator Switch
Most split systems have an isolator switch near the outdoor unit or on the wall. Make sure it hasn’t been switched off (it can be knocked or turned off during cleaning or maintenance).
4. Confirm the Mode and Settings
Check the unit is set to “cool” (or “heat”) and not on a timer or sleep setting that’s keeping it off. Try the manual ON button on the indoor unit — if it starts that way, the fault is the remote, not the air conditioner.
Common Reasons an Air Conditioner Won’t Start
- Tripped breaker or blown fuse — often an electrical fault if it keeps recurring
- Dead remote batteries or a failed remote
- Isolator switch turned off
- Faulty capacitor — the unit hums but won’t start
- Failed PCB (control board) — no response at all
- Compressor or wiring fault — needs a licensed technician
When to Call an Electrician
If the breaker keeps tripping, there’s no power at the unit, you smell burning, or the unit is dead after checking the breaker, isolator and remote, it’s time for a professional. Because an air conditioner runs on its own dedicated circuit, a “won’t turn on” fault is often electrical. Connex Electrical holds both an electrical contractor licence (QLD #92217) and an ARC refrigeration licence (#AU42842), so we can diagnose and repair the power supply and the unit together in one visit as part of our air conditioning service and repair.
What Does It Cost to Fix?
| Job | Typical Cost |
|---|---|
| Callout & diagnosis | From $88 |
| Labour (in-visit repairs) | $185/hr |
| Isolator / wiring repair | Quoted after diagnosis |
| Capacitor / PCB / compressor | Quoted after diagnosis |
Many “won’t turn on” faults are electrical and quick to diagnose. If it turns out the unit is beyond economical repair, we’ll tell you honestly and can quote a replacement installation.
Air Conditioning Service & Repair Across North Brisbane
Connex Electrical provides air conditioning service and repair for all brands across Brisbane and North Brisbane. If your unit won’t start, is tripping the breaker, or has no power, our licensed team will find the fault fast. For related help, see our guides on why your air conditioner is not cooling and what different air conditioner noises mean.
Reviewed by Lee Gundenswager (Lead Electrician, Connex Lic #92217) and Darren Standring (Owner).
Frequently Asked Questions
The most common reasons are a tripped circuit breaker, dead remote batteries, a blown fuse, or the unit being set to the wrong mode. Start by checking the switchboard for a tripped breaker and replacing the remote batteries. If the breaker keeps tripping or there’s no power at the unit, it’s an electrical fault that needs a licensed electrician.
A repeatedly tripping breaker usually points to an electrical fault — a short circuit, a failing compressor drawing too much current, or a wiring problem. Do not keep resetting it, as this can be a fire risk. Turn it off and have a licensed electrician inspect the circuit and the unit.
First replace the batteries, then check you’re pointing it at the indoor unit with nothing blocking the sensor. If a new set of batteries doesn’t help, the remote or the unit’s receiver may have failed. Many units have a manual ON button on the indoor unit you can use to test whether the fault is the remote or the air conditioner itself.
Many split systems can be reset by turning them off at the wall or the isolator switch for a few minutes, then back on. Some units have a small reset button on the indoor unit or remote. If a reset doesn’t restore power, or the unit trips again, it needs a professional — don’t keep power-cycling a faulty unit.
A callout and diagnosis starts from $88, with labour at $185 per hour. Simple faults — a tripped circuit, a faulty isolator, or a wiring issue — are often fixed in a single visit. Capacitor, PCB or compressor faults are quoted after diagnosis. As licensed electricians we can repair the power supply and the unit together.
Call a licensed electrician if the circuit breaker keeps tripping, there’s no power at the unit despite the breaker being on, you smell burning, or the unit is dead after checking the breaker and remote. Electrical faults must legally be repaired by a licensed electrician in Australia.
Air conditioner won’t turn on? Call Connex Electrical on 0474 207 609 or visit our contact page to book a licensed electrician across Brisbane and North Brisbane.