Condensate develops when water vapor in the air turns to liquid after coming in contact with the cold condenser coils of an air conditioner. In homes with central air conditioning, condensate pumps automatically remove condensate water. If a pump fails to operate, damage can occur to metal air ducts and the furnace plenum chamber where the condenser coils are located. You can replace the pump and install a Little Giant condensate pump with a few tools and basic do-it-yourself skills.
Set the heating and air conditioning thermostat to the "Off" position and turn off the power to the furnace at the main house panel.
Remove the service panel on the furnace to gain access to the condensate pump. Check your furnace manual if necessary to locate the panel and the pump assembly.
Remove the pump's three-prong power cord plug from its receptacle.
Locate the two 18-gauge safety shutoff wires on the condensate pump. Each wire has a wire nut attached to it. Remove the two wire nuts by turning them counterclockwise by hand and separate the wires.
Remove the condensate discharge tubing from its fitting by pulling it straight up and off. The tube is flexible and is secured to the barbed fitting by pressure only.
Remove the four retaining screws at each corner of the condensate pump mounting bracket, using the appropriate screwdriver. Turn the screws counterclockwise.
Raise the side of the pump opposite the condensate drain pipe until the pipe clears the cover of the pump reservoir cover. The clearance allows you to remove the old condensate pump.
Install the new Little Giant condensate pump by raising the pump to align the reservoir cover hole with the drain pipe.
Secure the Little Giant's mounting bracket with the four corner screws. Tighten the screws clockwise using the screwdriver.
Connect the condensate discharge tube to the barbed fitting. Press the tubing over the fitting until it is fully seated at the fitting's base.
Reconnect the two safety shutoff wires, using the wire nuts. Tighten the nuts clockwise by hand.
Connect the Little Giant's three-prong power cord plug into the receptacle.
Restore power to the furnace and turn the air-conditioning thermostat control to "On."
Test the Little Giant condensate pump by manually filling the reservoir with water. As the internal float assembly rises, the pump should become energized and the condensate should flow out from the discharge tube.
Replace the access panel.