The contactor is an electrical component which is part of a condenser. A condenser is an out-of-doors unit which is part of a heat pump. A heat pump is part of a heating, ventilation, and air conditioning (HVAC) system. When a contactor wears out, the condenser will not shut off when the thermostat tells it to. This means that your house HVAC system will not work as it should. A contactor wears out when its electrical contacts become pitted and corroded. To repair this, you must replace the contactor. Replacing the contactor will restore your HVAC system to proper operation.
Turn off the disconnect switch, which is in the disconnect box on the side of your house and connected to your condenser unit. The condenser unit is the large unit on the side of the house with the fan inside. Open the panel of the disconnect box to find the switch.
Turn off the air handler and condenser breakers on your house electrical panel.
Open the access panel on your condenser unit. This is the panel with the electrical warning sticker. Use the screwdriver to remove the screws and open the panel.
Unscrew the screw terminal holding each wire in place and remove the wires.
Remove the screws holding the contactor in place and remove the contactor.
Put your replacement contactor in the place of the old one and screw it in place.
Reattach the wires the way they were originally connected. Place each wire or wire terminal under the appropriate screw terminal, and screw the terminal into place. Repeat for each wire.
Turn on the breakers for your air handler and condenser on your electrical panel.