Preventive maintenance increases your air-conditioning system’s life expectancy and improves its energy efficiency.
Evaporator Coil Yearly Maintenance Clean

An air-conditioning system’s yearly preventive maintenance checkup should include one of three levels of evaporator coil cleaning: a yearly maintenance with a foaming aerosol coil cleaner, an in-place cleaning with a liquid coil cleaner, or when a licensed technician removes the coil from the furnace and gives it a chemical bath.

Condensing Unit Maintenance

A basic air-conditioning system’s condensing unit contains a refrigerant compressor, fan, capacitor, high-voltage relay and condensing coil. A basic heat-pump system’s condensing unit also uses a defrost circuit board and reversing valve. Both types of systems sometimes have upgraded items such as a hard-start capacitor for the compressor and a timer that prevents the system from restarting too quickly, such as when someone moves the thermostat temperature lever up and down repeatedly.

Drain Line Maintenance

When air passes over an air conditioner’s evaporator coil, the coil lowers air temperature and turns the humidity in the air into condensation. The condensation flows down the coil’s fins and gathers in the drip pan, where the water enters the drain line. The slow drip fails to create enough current to flush long drain lines, allowing sludge to form in the constantly wet section. Eventually the sludge dams the drain line.

Some air conditioning systems utilize an emergency float switch. The switch connects in series with the thermostat’s circuitry. A high water level in the drain pan makes the float switch open its contacts, turning off the air conditioning system.