How to reset your air conditioning unit when it's not working? A step by step guide

When you have a problem with a computer or other electronic device the first question you will often get from the manufacturer's help desk or warranty department is - "Have you tried turning it off and on?"

Your air conditioner is no different in this regard to other electrical appliances and may well benefit from a reset. An air conditioner reset takes no effort and may well avoid an unneeded service call.

Reasons You May Need to Reset Your Air Conditioner

  1. Air Conditioner showing an error.Any time your air conditioning system is showing and error the first thing we would recommend is that you carry out a hard reset on the air air conditioner. Some errors are intermittent in nature and a reset of the ac unit may resolve the error
  2. Your air conditioner will not start or has stopped for no reason.Intermittent environmental factors like a power outage or a problem with the quality of your external power supply may cause your air conditioner to stop. A reset will often resolve these issues.
  3. Air conditioner running but not cooling \ heatingIf your ac unit is blowing warm air when it supposed to be blowing cold air it is a sign that the refrigeration circuit has not activated. This may be due to something as simple as a lock up in your controller which like all electonic components may be resolved by a reset.

What Happens When You Reset Your Air Conditioner?

When you reset your air conditioner it erases all faults and puts the system in a state where it is attempting a fresh start. If the fault that has caused your air conditioner to stop is intermittent or environmental then a reset may resolve your issue.

How do I reset my air conditioner

Here are the steps you should follow to reset your air conditioner

  1. If the system is on - turn it off with your controller
  2. Locate the outdoor unit
  3. Locate the isolator switch - a large plastic switch - typically located on the wall beside the outdoor unit. Most air conditioning units in Australia have one of these - one installed in the last 10 years almost certainly will.
  4. Turn the isolator to the off position
  5. Leave the isolator off for 30 minutes
  6. Turn the isolator back on
  7. Check to see if the errors have resolved themselves

We call this a 'hard' reset - which you won't achieve if you just switch the isolator off for a few seconds and then turn it on.

Some air conditioners in overseas markets have a reset button - but a reset button is not a common feature on air conditioners sold in Australia.

reset button

How to reset my air conditioner if it doesn't have an isolator?

If your air conditioning unit was installed some time ago it may not have an isolator. In that case you can reset an air conditioner by finding the circuit breaker box (switchboard) and switching the circuit breaker off for 30 minutes. You should then switch the circuit breaker on and see if the fault has been rectified.


What should I do if after resetting my air conditioner it is still not working or has an error?

If your air conditioning units don't start working after you have done the reset - this means your ac unit should be diagnosed by a professional technician.

At Sun City Air Conditioning we carry out over 5,000 jobs per year. Our combined experience, together with our trained and knowledgeable tradesmen mean we are perfectly placed to diagnose and repair your air conditioner.

Brisbane Air-Conditioning services you can trust

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