A drain pump is an alternate method for water removal when gravity cannot provide the needed drainage. Instead of waiting for water to go down the drain, the user activates the pump to pull water out of a particular area, as in a kitchenette or wet bar.
Drain pumps that do not require venting or inlet piping simply remove the excess water from an appliance, sink or other location, ferrying it to a safe place for wastewater disposal. Rather than waiting for the user to turn the pump on, many models come with a pressure switch so that the pump activates instantly when water begins draining from the sink or other collection area. When the water is gone, the lack of pressure deactivates the switch.
Some characteristics to look for in a quality drain pump include quiet operation and a compact size. In many areas that require a drain pump, there is not a lot of room beneath the sink for large pump. A reservoir-type drain pump is desirable when the pump has to serve more than one drainage source, such as in a double sink in a laundry room or kitchen. Reservoir-style pumps sometimes offer more durable construction than those that directly mount, depending on the manufacturer.