How to Fix a Broken Air Con Unit

Last Updated on

Air conditioners work hard throughout the year to keep us cool, but we often don’t realize how much we rely on them until they break. If your air conditioner suddenly stops working, there’s no need to immediately call out a professional – the solution might be easier than you think. Here are some tips on how to fix a faulty air conditioner unit and get it back to full health. 

What's Inside?

Check the Thermostat


Most thermostats are battery-operated so once they power down, the air conditioning unit goes with it. But it could be as simple as checking that the thermostat is working correctly and making sure that all the connections to the wall are in place securely. 

Check the Fuses

If the air conditioner has been running for a long time, it can trip an electrical breaker which will blow the fuse. Make sure this hasn’t occurred by checking the fuse box and use a multi-tester to check that the fuses inside the disconnect block to make sure they’re still working as they should. It can take as long as 20 minutes for the air conditioner to be running again once it’s tripped a fuse or the power is turned off, so be patient before trying out another solution. 

Replace the Filter

ac filter

A clean filter is the key to an efficient and well-functioning air conditioner, so if you’ve been a bit lax with changing out the filters this could be the cause of your problem and you’ll need to find an air filter. This is especially the case if you have pets, leave windows open or you have allergies, as you may need to change the filter more often in these cases. Make sure the vents around the unit are clean and that there is plenty of space around the unit to provide ample air flow. 

Check the Access Panel

Turn off the main power to the box before opening the access panel to the air con unit. This is usually situated where the electrical power comes from – check that there are no broken wires or that none of the connections have become frayed, as this can often be to blame for a faulty air conditioner. 

Replace the Contactor

The contactor is the relay which converts the low voltage signal from the thermostat to a signal that switches on the compressor and condenser. If this fails, the unit will also fail. But the good news is that while it sounds complicated, these are actually cheap and easy to replace – you just need to find your user manual to identify where the contactor is on your particular model and the type you need to replace it with. 

Replace the Capacitor

An electrical capacitor stores electricity and is used when the compressor and fan start working for an additional boost of power. The capacitor also protects the motor from damage from fluctuating voltages. If you’re not phased by electrical repairs, Capacitors can be fixed without professional help – use a screwdriver to discharge the capacitor by connecting terminals to short it out and replace it with a new one that matches your model of A/C unit. 

Related reading:

Read more

Read more

Read more

Read more