Condensate pump

If the liquid continues to rise (perhaps because the pump has failed or its discharge is blocked), the second stage will be triggered.

This stage may switch off the HVAC equipment (preventing the production of further condensate), trigger an alarm, or both.

This second stage action is in addition to any triggering of other system changes as noted for a single pump installation.

The smallest pumps may have no tank at all and are simply placed within a container such as the drip pan of a dehumidifier appliance.

This pump sends the water to a make-up tank closer to the steam generator or boiler.

Two pumps in succession are used to provide sufficient net positive suction head to prevent cavitation and the subsequent damage associated with it.

Some systems are so remote that steam power is used to return the condensate where electricity is impractical to provide.

If the outlet is below the tank level, siphonage usually naturally clears the output line of all liquid when the pump is de-energized.

In one case, a 2,600 US gallons per minute (160 L/s) steam condensate pump exploded when it was operated with its suction and discharge valves closed.