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Air Conditioner Parts and What They Do
How each part of a air conditioner works, the signs it is failing, which error codes point to it, and whether you can replace it yourself.
17 air conditioner parts
- CompressorTechnician job
The pump inside the outdoor unit (or in the back half of a window or portable unit) that moves refrigerant around the system.
21 related codes
- Refrigerant charge and line setTechnician job
The copper line set that links the indoor and outdoor units, the refrigerant inside it, and the service valves on the outdoor unit where the lines connect.
15 related codes
- Electronic expansion valveTechnician job
A motor-driven metering valve, usually in the outdoor unit, that controls how much refrigerant flows into the coil that's doing the cooling or heating.
8 related codes
- Reversing (4-way) valveTechnician job
Found only on heat pump models, this brass valve near the compressor in the outdoor unit switches the direction of refrigerant flow.
3 related codes
- Pressure switch and sensorTechnician job
Safety and control devices on the refrigerant lines in the outdoor unit.
3 related codes
- Outdoor control and inverter boardTechnician job
The electronics in the outdoor unit, sometimes on one board and sometimes split in two.
54 related codes
- Indoor control boardTechnician job
The main board inside the indoor unit, behind the front panel or in the control box.
43 related codes
- Temperature sensors (thermistors)Technician job
Small sensors on wires clipped to pipes or sitting in the airflow.
43 related codes
- Indoor fan motor and blower wheelTechnician job
The long cylindrical blower (cross-flow wheel) in a wall unit, or the squirrel-cage blower in ducted and ceiling units, and the motor that drives it.
12 related codes
- Outdoor fan motor and bladeTechnician job
The large propeller fan in the outdoor unit and the motor behind it.
16 related codes
- Indoor and outdoor coilsTechnician job
The finned copper or aluminum heat exchangers.
3 related codes
- Air filterEasy to replace yourself
The mesh screens that snap in behind the front panel of a wall unit or the return grille of a ceiling or ducted unit.
15 related codes
- Condensate drain line and panEasy to replace yourself
The tray under the indoor coil that catches water dripping off it, and the hose or pipe that carries the water outside or to a drain.
8 related codes
- Condensate pump and float switchTechnician job
Ceiling cassettes and ducted units that can't drain by gravity use a small pump to lift water out.
9 related codes
- Indoor-outdoor communication cableTechnician job
On most mini-splits, the cable between the indoor and outdoor units carries both power and the data signal the boards use to talk.
11 related codes
- Power supply wiringTechnician job
The dedicated circuit from your panel, the disconnect box near the outdoor unit and the wiring into the units.
7 related codes
- Wired remote and Wi-Fi adapterTechnician job
The wired wall controller, plus add-on adapters that plug into the indoor unit.
5 related codes