A window unit, commonly called a window air conditioner, is great for cooling a single room or a group of rooms that do not have partition walls. A window air conditioner consists of a blower, fan, compressor, evaporator coil, condenser coil, thermostat and filter.
Internal maintenance to the sealed refrigeration circuit (coils, compressor and motor) should be left to a trained technician. There are minor steps that you can take to keep your window air conditioner running strong.
During the winter months, window units should be removed and stored indoors in a clean, dry area. If you are storing your window air conditioner in the basement, be sure to elevate it to make sure it does not get exposed to water. Always keep your unit in the upright position to prevent oil and refrigerant migration.
Warning: Before any work is done on your appliance, it should be unplugged and discharged. Failing to do so could result in severe, and potentially lethal, electrical shock.
Maintaining Basic Components
(THESE PROCEDURES SHOULD ONLY BE ATTEMPTED BY A TRAINED TECHNICIAN)
The filter, power cord, coils, switch, thermostat, drain ports and fan are important to service on a routine basis to avoid serious problems. Typical guidelines for maintaining these parts are as follows (BE SURE TO REFER TO YOUR OWNER'S GUIDE FOR SPECIFICS ON YOUR UNIT):
Filter
Before every cooling season and once a month during the cooling season, the filter should be removed, cleaned and replaced. If you live in a particularly arid climate, this may need to be done more frequently. Most window air conditioners have a washable filter that looks like a sponge.
Clean filters with a mild detergent and water, rinsing well. Let the filter dry completely before replacing. If your window air conditioner comes with a fiberglass furnace style filter, do not wash it; replace it with a new filter of the same type.
Power Cord
If your air conditioner stops working and you suspect that it is not getting power, there could be a problem with the power cord. Power cords may become worn and fail to supply electricity to the air conditioner. To check the cord, remove the control panel. Unscrew the cord terminals and then attach a test wire across the bare lead wires.
Hook the clips of a volt-ohm-millimeter (VOM) set to the RX1 scale to the prongs on the cord's plug. If the meter reads zero, the cord is functioning. If the meter reads higher than zero, replace the cord.
Evaporator and Condenser Coils
Clean the evaporator and condenser coils the same time you clean the filter; before the start of the cooling season and once a month during the season. If your area is particularly dusty, this may need to be done more frequently. The coils can be cleaned with a vacuum cleaner hose. If the fins on the coils become bent, use a fin comb from your local hardware store to straighten them.
Switch
The selector switch, behind the control panel, turns the window air conditioner on and off. If the air conditioner does not run on any setting, and you have already made sure that the power cord is working, you may have a faulty switch. To check, remove the control panel and see if there is burnt insulation or black marks on the terminals. If so, replace your switch with one of the same type.
Thermostat
The thermostat is also located behind the control panel. If you believe you have a problem with your thermostat, here is how to test and replace it:
1) Remove the grille and control panel. There will be a temperature sensing bulb extending from the thermostat to the face of the evaporator coil
2) Carefully remove the thermostat, noting the position of the sensing bulb. It must be replaced in the exact spot.
3) Check the thermostat with the VOM setting on the RX1 scale. Clip the probes to the thermostat terminals and turn the temperature control to the coldest setting. Your meter should read zero if the thermostat is working properly. If the reading is greater than zero, replace the thermostat with a new one of the same type.
Drain Ports
The evaporator coil condenses water vapor from the air and funnels it through a drain port. At this point, the water is blown against the condenser coil, where it is dissipated.
Drain ports can become dirty and get clogged with debris. This results in water leakage, usually through the bottom of the front grille. To prevent clogging, clean the drain with a piece of wire. Do this at the beginning of every cooling season and when your unit starts to leak.
Fan
If your fan is not working or if it is particularly noisy, it is usually caused by loose or dirty fan blades. Follow these steps to repair the fan:
1) Locate the fan inside the cabinet.
2) Use a soft cloth and/or vacuum to clean out any debris.
3) Check tightness of all blades. Vibration can loosen fan fasteners. Use a screwdriver or Allen wrench to tighten screws that connect the fan hub to the motor shaft.
4) If your fan has oil ports, apply a few drops of 20-weight non-detergent motor oil.
5) If you suspect a faulty motor, test with the VOM on the RX1 scale. Connect VOM probes to disconnected terminal wires.
If the meter reads between 3 and 30 ohms, your motor is functioning properly. If your meter reads zero or it is extremely high, replace the motor.
To remove the fan motor, remove the fan blades, power wires and mounting bolts. Install a new motor by reversing this procedure. If the condenser coil prevents motor removal, do not attempt to remove the motor. Call a professional.
If any other problems occur with the motor, compressor or coils, a professional service person should be called.
By doing simple maintenance and repairs as described in this article, you can significantly extend the life and efficiency of your window air conditioner.
