How to Fix a Window Air Conditioner that won't Turn On

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.  

Window air conditioning system or machine is similar to any other air conditioning system. Major components of a window air conditioner are: the evaporator coil, fan or cool air blower, thermostat, and air filter. Plastic cabinet and components like a compressor, condenser coils and condenser fan and a drain pipe (to drip the moisture condensate from the evaporator coil) are also other important components. Most of the times, a minor problem in any of the above mentioned components is the spoil sport. Such problems can be fixed as follows.

Problem 1 – Check the Power Supply

Check whether the power cord is completely plugged in and there are no visible cuts or breakages on it. If the power cord is cut, fix it accordingly. Plug in the power cord correctly and test run the air conditioner.  

Problem 2 – Fuse

A window air conditioner won’t turn on if the fuse of the power supply to the unit has blown. If that is the case, fix it by replacing the fuse wire. Check the machine by running it again. If the fuse blows off again, then provide a dedicated 120 volts plug in facility to the unit. The reason is, 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.

Problem 3 – Circuit Breaker

If the fuse is also intact then check whether the breaker in the circuit had tripped, if so reset the circuit breaker and start the machine again. 

Problem 4 – Thermostat

Check the temperature of the thermostat, if it is way off the mark, set it to a correct temperature. Else, check if the thermostat is stuck at a particular temperature. This will happen only if the filter has become dry due to dirt accumulation or dead batteries. Fix the problem of the filter either by cleaning, replacing or charging the batteries. At times, the filter gets stuck and if this happens, the machine can’t operate as the evaporator coil freezes. 

Problem 5 – Other Common Problems

Check if the air conditioner is choked 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, it damages the capacitor and in extreme cases, the air conditioner can also be blown. So, clear the debris and other vegetation growing around the air conditioner.

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