A condensate pump is a pump designed to be used with air conditioners, refrigerators and other appliances that create a buildup of water. The water condensates from water vapor that is created from steam, exhaust or warm air meeting a unit that is cool. The pump removes water from the system and pumps it through a pipe, normally to an outside drain.
The pump is triggered when a float in the water reaches a height. This triggers a switch that turns the pump on. Once the float goes down to a lower level, the float signals the pump to turn off. Some pumps have a safety switch that turns the entire system off if the pump fails to turn on when needed. It does this at a second switch higher than the first. If the float reaches the second switch, the system turns off to keep the condensation tank from overflowing.