Your home's central air conditioner is a multi-part unit that includes the interior air handler within your furnace and an exterior condensing unit, which is where the cooling process starts. The condensing unit is also where many cooling-system problems trace back to, since the unit has so many vital components.

Here are three key parts that keep your air conditioner's condensing unit functioning and how problems there can thwart your entire system. If you do suspect a problem, contact an air-conditioning repair company such as LSM-Lee's Sheet Metal Ltd as soon as possible.


The compressor is the motor that starts up and powers the condensing unit. The fuel in the motor is a gas chemical called refrigerant. When the compressor fires up, that part pushes out gas refrigerant into the nearby condenser coils in order to kick off the cooling process. If the compressor fails to push out refrigerant, your system isn't going to function at all.

Problems with the compressor are typically electrical issues. If you don't hear your condensing unit kick on at all when you turn down the thermostat, the compressor might be the culprit. The fix is often just to replace the compressor, and this is a job you want to leave up to the professionals. Installing a new compressor incorrectly can cause irreparable damage to your central air-conditioning system and leave you with more problems than when you started.

Condenser Coils

The condenser coils receive the gas refrigerant from the compressor and then work some phase-change magic to change that refrigerant into a liquid. The refrigerant needs to become a liquid in order to move through lines into your house, where the liquid enters evaporator coils and provides the cooling needed to make your home comfortable.

If dirt clogs the surface of the coils, the phase change won't carry out correctly, and you can lose efficiency in your system. You can clean the coils yourself by carefully spraying a hose from the inside of the condensing unit. Make sure you turn off all electricity to the unit first.

Bends or breaks in the coils can also interfere with the phase change and potentially cause a loss of refrigerant. Call an HVAC technician to completely replace the coils.

Motorized Fan

Condenser coils become hot during the phase-change process. A motorized fan points at the coils to keep the surface from becoming too hot. This would interfere with the phase change but also risk causing the unit to overheat. If the condensing unit senses overheating conditions, the unit will shut itself off as a safety mechanism.

Stand near your condensing unit and listen for the sounds of the fan as the system runs. If you don't hear the fan at all, the motor might need replacing.