Find Out How To Maintain A Window Air Conditioner

Window units, also known as window air conditioner models, are perfect for cooling down a single room or several rooms that lack partitions. Each model has a compressor, fan, blower, condenser coil, evaporator coil, filter and thermostat.

The sealed refrigeration circuit, which consists of the compressor, motor and coils, must be maintained internally by a trained professional.

There are several small steps that you can still take, however, to ensure that your window unit continues to function optimally so long as you learn how to maintain a window air conditioner properly.

Throughout the cold months of winter, you should remove your window AC and store it in a dry, clean area indoors.

If you intend to stow this equipment in your basement, you should always elevate it in order to limit the likelihood of water exposure. Make sure to keep it in an upright position as well so that the refrigerant and oil do not migrate.


Before performing any type of work on these appliances, they must be unplugged and discharged. If you fail to do this, this could result in severe and possibly fatal electrical shock.

Maintaining The Basic AC Components


The power cord, filter, thermostat, switch, fan and drain ports must be regularly serviced in order to keep major problems at bay. The standard guidelines for caring for these components are as follows (ALWAYS REFER TO THE OWNERS GUIDE FOR INSTRUCTIONS THAT ARE SPECIFIC TO YOUR UNIT):


Before each hot season hits and once per month throughout the hot season, you should remove your filter and clean or replace it.

If your region is very arid, this is something that you may need to do more often. A lot of window AC units have filters that look like sponges and that can be washed.

You can use water and a mild detergent to clean your filter but you should make sure to rinse it thoroughly.

The filter should be dried completely before it is replaced. If you have a model with a fiberglass furnace filter, replace it rather than washing it and make sure to get the exact same type of filter when purchasing the replacement.

Power Cord

If your unit stops functioning and you think that it might not be getting power, the power cord may be having an issue.

These cords can start to wear down and will eventually become unable to supply electricity to the unit. Inspect the power cord and remove the control panel. Take the screws out of the cord terminals and then connect the test wire across the bare lead wire.

The VOM or volt-ohm-millimeter clips should be set to the RX1 scale and then attached to the prongs on the plug for the cord. If a zero meter reading is received, the cord is working just fine. You will have to replace the cord if the meter reading is higher than zero.

Condenser and Evaporator Coils

The condenser and evaporator coils should be cleaned at the same time that the filter is cleaned; once each month throughout the hot season and just before the hot season hits. If you live in an area that has a lot of dust, this will need to be completed more often.

You can use your vacuum cleaner hose to clean the coils. Should the coil fins get bent, visit a hardware store to secure a fin comb that can be used to straighten them.


Behind the control panel, you will find a selector switch that is used to turn the unit off and on.

If the AC is not functioning on any of the available settings and you have already checked to ensure that the power cord is functioning, your switch could be faulty. To check this out, remove the control panel and look for blackened terminals or burnt insulation.

If you find these, replace the switch.


The thermostat can also be found behind the control panel. If you think that the thermostat is not working, here is how you can test your thermostat and replace it, should this prove necessary.

1. Take the control panel and the grille off. You will find a temperature sensing bulb that extends from the thermostat to the front portion of the evaporator coil.

2. Take the thermostat out while using great care and while considering the position of the sensing bulb. You will have to replace this exactly as you found it.

3. Use the VOM setting on the RX1 scale to check the thermostat. The probes should be clipped to the thermostat terminals and then you can move the temperature control down to its lowest possible setting.

If the thermostat is working like it should, the meter will read zero. When the meter reading is greater than zero, you will need to replace your thermostat with the exact same type.

Drain Ports

Water is condensed from the air by the evaporator coil where it is funneled through a drain point. At this time, the water is pushed against the condenser coil and dissipates.

Debris can clog drain ports and make them dirty. The result is often water leakage at the bottom portion of the front grille. To keep these ports from getting clogged, use a piece of wire to clear the drain. You should do this just before the hot season arrives and whenever this equipment begins to leak.


If your fan is very noisy or if it is no longer working, this could be caused by fan blades that have become dirty or loose. You can use these steps to fix your fan:

1. Check inside the cabinet to find the fan.

2. Use a vacuum or soft towel to remove all dirt and debris.

3. Check to ensure that the blades are sufficiently tight. Vibration can cause the fasteners to become loose. Use an Allen wrench or screwdriver to tighten up the screws that secure the fan hub to the unit’s motor shaft.

4. If there are oil ports in the fan, place several drops of a 20-weight, non-detergent motor oil on these.

5. If a faulty motor is suspected, use the VOM on the RX1 scale to test it. The probes for the VOM should be connected to the terminal wires after these have been disconnected from the terminal.

The motor is functioning like it should when the meter reading is between three and 30 ohms. If you have a very high meter reading or if it reads zero, your motor will need to be replaced.

When removing the fan motor, take out the fan blades, then the power wires and finally the mounting bolts. Reverse these steps to put a new motor in. If it is not possible to remove the motor due to the condenser coil, call a professional instead.

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