Window Air Conditioner Problems:


Begin your window air conditioner troubleshooting by ensuring that the routine maintenance has been performed on the unit.


Then, your window air conditioner troubleshooting should start with checking the different modes of operation to see which components operate. Turn the unit fan to on and the cool and heat modes off. If the fan does not operate, check the power supply to the unit. Check to see if the breaker or fuse for the unit is tripped. If the breaker/fuse is tripped, check to make sure that it is the proper size circuit for the unit you have. On some units, there is a current interrupter on the power cord to the unit. Check to see if it is tripped by pushing the reset button.


If the circuit is the proper size, then you can go ahead and reset the breaker/fuse. If it trips again, then you require further troubleshooting. Shut the power off and check all of the wiring in the unit to make sure that none of the connections is loose or damaged.


If the fan does not operate but the fuse/breaker is not tripped, you should check the run capacitors for the fan and compressor. If the capacitors are good but the fan motor does not operate, you can check the fan switch and the fan motor. Ensure that the fan blades spin freely.


If the fan motor operates but the compressor does not start, you should feel the compressor with your hand. If it is very hot, then you should allow it to cool. Then, you can take resistance measurements to make sure the compressor motor is good.


Then, you should attempt to start the unit in the cooling mode. As you do so, listen for a clicking sound which is an indication that it is attempting to start. If the compressor starts but does not cool properly, the unit may be low on refrigerant.


If the compressor attempts to start but shuts off very quickly, the compressor could be bad. Generally, if the compressor is bad on a window air conditioner, it is cheaper to replace the entire unit than to fix it.

You can check out our brand ratings to help you to choose the right brand to replace your broken unit.

If the compressor does not attempt to start, ensure that the thermostat is set below room temperature. On units with a mechanical control, you will hear a click when you adjust the temperature. That is an indication that the thermostat is working properly. On units with an electronic control, you can take a resistance reading of the temperature sensor to verify it is good. If the sensor is good and the compressor checks ok, then the control board is probably bad.


You should complete your window air conditioner troubleshooting by observing the unit's operation through a complete cooling cycle. During this time you should check the difference between the temperature of the air entering the unit and the temperature of the air leaving the unit. There should typically be a ten to fifteen degree difference.


Buying A Window Air Conditioner

Before you buy a window air conditioner, there are some basics you should know. These units work in much the same way as a central air unit. They are often referred to as a room air conditioner because of their limited capacity to cool. They usually range from 5000 to 24000 btu

The main advantage of these units is that they are inexpensive to buy and are relatively easy to install.

Their biggest disadvantage is that they are usually not very efficient. Therefore the amount you save in purchasing them is usually wasted quickly in operating costs.


The efficiency of these units is given as an EER number. EER stands for energy effiency ratio and is the cooling output of the unit divided by the power required to produce the rated cooling. For a given size unit a higher EER number means less electricity is required to run the unit.


These units come in a variety of models. There are cooling only units, cooling units with electric heat, and Heat Pumps units. They can be either mechanically or electronically controlled.

The latest innovation is called low profile window air conditioners. These units are shorter and wider than the typical unit. This allows the window to be more fully closed which allows a more normal view out of the window.

There are also many options such as anti-bacterial filters, charcoal filters, and electrostatic filters. Some units can be operated by remote control.


When you go to purchase them you need to take some information with you. You need to know the size and type (casement or double hung) of the window it will be installed in.


These units come in 120 volt or 220 volt. Therefore, you need to know what voltage you have close to the window as well as the available amperage of the electrical circuit. This can usually be found by the type of receptacle that will be used. These units should not be plugged into an extension cord!


The last thing you need is the size of the room in square feet.  The only way to accurately find out what size is required is through a process called a load calculation . Home Depot or Lowes is a perfect place to buy window A/C. Make sure you buy the extended warranty.


Like any hvac unit, these require routine maintenance.


Other options, such as ductless ac units, should be considered before buying. If you already have a central heating system, consider adding central air. These units will cost more but will usually quickly pay for themselves. Give us a call for these units.