What are the most common window air conditioner replacement parts?

You rely on your window air conditioner to keep you cool in the summer. When it stops cooling, or your air conditioner stops working altogether, you’ll want to fix it fast.

Smaller room air conditioners can sometimes be carried in for service at a local appliance repair facility, but taking the room air conditioner out of the window can be a tedious and complicated task. Fixing a broken room air conditioner on your own can often save you time, trouble and money.

Use the troubleshooting tips in our DIY window air conditioner repair help section to diagnose a room air conditioner failure and find out which part needs replacing. We describe common symptoms and provide troubleshooting solutions for any make or model of room air conditioner. We offer window air conditioner repair guides that walk you through repairs step by step.

Sears PartsDirect has replacement parts for many major brands of window air conditioners including Amana, Carrier, Emerson, Frigidaire, GE, Haier, Kenmore, LG, Panasonic, Sharp and Whirlpool. To find a complete list of replacement parts for your window air conditioner, enter the model number in the search field at the top of the page.

What are the most common control parts that need replacing in room air conditioners?

Electronic control board

The electronic control board controls the major electro-mechanical components in the window air conditioner. The electronic control board receives input from temperature sensors to monitor the temperatures inside the room and at the evaporator. With this information, the electronic control board manages the on/off cycling of the compressor to cool the room to the set temperature. The electronic control board activates the compressor and fans when it senses that the room temperature exceeds the set temperature. If the electronic control board doesn't activate those components properly, replace the control board.

Control thermostat

Some window air conditioners have an electro-mechanical thermostat instead of an electronic control board to control the on/off cycling of the compressor and fans. The control thermostat is mounted on the control panel. A knob on the front of the control thermostat is rotated to set the desired room temperature. The control thermostat senses the room temperature through a sensing bulb and cycles the compressor on and off to maintain the room temperature that is set. Replace the thermostat if it fails to control the compressor and fans properly.

User interface control board

The user interface control board is a circuit board with selection buttons and display components, which is mounted on the control panel of the air conditioner. The user interface control board sends signals to the electronic control board to communicate the window air conditioner’s settings. If the display won't light up or if the control panel won't respond when you select a button, you may need to replace the user interface control board.

Control panel

The control panel houses the selection buttons and display components for the room air conditioner. You may need to replace the control panel when selection buttons or the display quit working.

Wire harness

The wire harness is a collection of wires, cut to specific lengths, that connects the various components in the window air conditioner. The ends of the wires typically have connection plugs or spades so that they attach to the correct components in the window air conditioner.

Ambient thermistor

The window air conditioner ambient thermistor-also known as a temperature sensor-senses the temperature of the air entering the air conditioner and communicates that temperature to the electronic control board, which cycles the compressor on and off to maintain the set room temperature. The ambient thermistor is attached to the evaporator coil that's behind the air filter, and a wire harness connects the ambient thermistor to the electronic control board. If the ambient thermistor is defective, the electronic control board will not cycle the compressor on and off properly to maintain the room temperature that is set on the control. Replace the ambient thermistor if it doesn't accurately measure the ambient room temperature.

Evaporator thermistor

The evaporator thermistor is a temperature sensor that is mounted on the evaporator. It monitors the temperature of the evaporator to detect excessive frost on the evaporator. The thermistor communicates that temperature to the electronic control board through a wire harness connection. If the evaporator frosts up, the electronic control board will detect the frost according to the temperature communicated through the thermistor. If the thermistor is defective, the electronic control will not properly detect and eliminate the frost. Replace the evaporator thermistor if it doesn't properly detect the evaporator temperature.

What are the most common fan replacement parts in window air conditioners?

Condenser fan

The condenser fan moves air across the condenser to enhance the cooling process of the hot, compressed refrigerant that flows through the condenser. The air conditioner won’t cool properly when the condenser fan is broken. Replace the condenser fan if it doesn’t run even though it gets power from the control.

Blower fan motor

The blower fan motor spins the blower wheel that circulates air through the evaporator and into the room for cooling. Replace the blower fan motor if it doesn’t spin the blower wheel when the motor gets power from the control.

Blower wheel

The blower wheel attaches to the blower fan motor shaft and rotates to circulate air through the evaporator and into the room for cooling. Replace the blower wheel if it’s damaged.

Blower wheel bearing

The blower wheel bearing supports the blower wheel shaft while allowing the shaft to spin freely. The blower wheel won’t spin if a blower wheel bearing seizes up. You’ll typically hear a whining or squealing sound when a blower wheel is worn and needs replacing.

What are the most frequently replaced cooling system parts of a window air conditioner?

Air filter

The window air conditioner air filter screens dust and lint from air that circulates through the window air conditioner. Clean the air filter regularly to keep air flowing through the room air conditioner properly. Replace the air filter if it’s torn or damaged.

Compressor capacitor

The compressor capacitor briefly increases the voltage to the compressor to help the compressor start. The compressor won’t start when the capacitor is bad. If you hear the relay click to turn on the compressor but the compressor motor won’t start, you may need to replace the compressor capacitor.

Compressor overload

The compressor overload is a protection device in the compressor circuit. The compressor overload trips to cut off voltage to the compressor if the compressor locks up or draws too much current. Excessive current draw causes the compressor and wiring to become hot. The compressor overload resets automatically when the compressor, wiring and the compressor overload cool to a normal operating temperature. The compressor won’t start when the overload is bad.

Condenser

The condenser is a heat exchanger that cools and condenses the hot, high-pressure refrigerant gas to a liquid. The refrigerant then flows through the evaporator in the window air conditioner. In the low-pressure environment of the evaporator, the liquid refrigerant from the condenser evaporates to a gas. During this evaporation process, the refrigerant absorbs heat from the air that the evaporator fan blows across the evaporator fins. The cooling of the refrigerant in the condenser increases the efficiency of the heat exchange process in the evaporator. If the condenser leaks refrigerant, you’ll need to have a refrigerator service technician replace it; a licensed technician must do this repair because it involves recovery and recharge of refrigerant.

Evaporator

The evaporator is the heat exchanger that provides the cooling for the window air conditioner. Low-pressure liquid refrigerant moves through the evaporator where it turns to vapor. The latent heat of vaporization is absorbed from the air that’s blown across the metal fins in the evaporator, cooling the air. If the evaporator gets damaged or leaks refrigerant, you’ll need to have a service technician replace this part because the repair involves recovery and recharge of refrigerant.

Compressor

The compressor receives low-pressure refrigerant gas from the evaporator and rotates to compress that refrigerant to a high-pressure gas that moves through the condenser. The refrigerant gets hot when compressed by the compressor pump. The condenser is a heat exchanger that removes heat from the refrigerant gas and condenses it into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the expansion device and into the evaporator that's at low pressure. The high-pressure refrigerant expands and evaporates. It absorbs the latent heat of vaporization as it changes from a liquid to a gas, which causes the cooling action in the evaporator. The refrigerant flows through the evaporator and back to the compressor where the cycles starts over. If the compressor doesn't run when activated, schedule a refrigeration service technician replace it; by law, an EPA-licensed technician must do this repair because it involves recovery and recharge of refrigerant.

How can I get replacement installation parts for my window air conditioner?

Window air conditioner installation parts eventually wear out and need replacing. You may also need replacement installation parts if you move a room air conditioner to a different window or location.

To find replacement installation parts for your window air conditioner, key the model number of your window unit into the search bar at the top of the web page. You’ll find the installation parts listed in the parts list diagram for your model of air conditioner.

Here is a brief list of common window air conditioner installation parts that commonly need replacing:

• Accordion window filler. The accordion filler attaches to the outer cabinet and fills the space left open between the cabinet and window frame when extended.

• Window foam seal. The window foam seal fits between the air conditioner cabinet and the window opening to prevent outside air leaks into your home.

• Support bracket. The support bracket levels and stabilizes the air conditioner cabinet from the outside of your home.

Follow the instructions in the owner’s manual for your air conditioner to install replacement installation parts or to use installation parts to insert the air conditioner in a new window.