5 Reasons Your Window Air Conditioner Isn’t Working 5 Reasons Your Window Air Conditioner Isn’t Working

What You'll Need

Window air conditioners at times just refuse to turn on. In most of the cases, the problem is a minor one and can be taken care of at home without getting a professional help. A little general knowledge about window air conditioners will help you to understand and rectify the associated problems in a better way.

So, before you toss your old AC unit or call a repairman, check these five common problem areas and give DIY repairs a try.


1. Basic Power Capabilities

Check whether the power cord is completely plugged in; sometimes outdoor outlets or older outlets don't secure the plug tightly enough and need to be tended to.

Then check the cord to see if there are any visible cuts or breakages on it. If the power cord is cut, safely unplug the unit and take the appropriate measures to fix the broken areas.

If your window unit’s button interface is worn and can’t be trusted, you can also consider buying a cheap universal AC remote or replace the worn switch. If you suspect this is the case, it means the unit is not broken, just that you have no way of communicating what you want the machine to do.

2. Fuse Box

A window air conditioner won’t turn on if the fuse of the main power source to the unit has blown. If that is the case, fix it by replacing the fuse wire.

Once the fuse has been replaced, check the machine by running it again. If the fuse burns out again, provide a dedicated 120 volt plug for the unit. If the air conditioner draws power from a circuit shared by other appliances, it can’t draw required power supply and will blow the fuse repeatedly. By providing its own high-voltage plug, it can run smoothly with fewer interruptions.

NOTE: Because of the power demands of an air conditioning unit, it may trip the safety buttons on certain outlets and the plugs will need to be reset to eventually restore power. Always check this as well.

3. Circuit Breaker

A similar protocol should be followed if you have a circuit breaker. If your AC won't turn on, check to see if the breaker has been tripped. If so, reset the circuit breaker and start the machine again. If it goes off again, you may need to rewire in order to provide a 120 volt circuit that operates only the AC unit.

4. Thermostat and Filters

Check the temperature of the thermostat on your unit. If it the unit is set to "heat," it won't turn on. If it is set properly, try lowering the thermostat slightly to see if it makes a difference. Sometimes the thermostat gets stuck, but you don't know because it appears to be set properly. This is why it is important to make adjustments as you troubleshoot.

If adjusting the thermostat doesn't make a difference, you more than likely have an air filter issue. When the filter becomes dry due to dirt accumulation, the thermostat can get stuck and the unit will stall. You can fix the problem by cleaning or replacing the filter. At times, the filter can even get stuck from accumulated debris, and if this happens, the window air machine can’t operate as the evaporator coil freezes. That is why checking the thermostat is such an important troubleshooting step.

5. Clogs in the Unit

Check the air conditioner as a whole to see if it is plagued with the debris or plant growth. A window air conditioner needs to circulate air, and if debris like grass or other objects get sucked in, the capacitor can be damaged, and in extreme cases, the air conditioner can also be blown. So, clear the debris and other vegetation growing around the air conditioner.

When to Seek Professional Help

If all the above mentioned methods fail, then a problem originating in the compressor, condenser, or evaporator might be the culprit. If that is the case, you have no option but to get a professional help.

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