Booster Pump

A booster pump sits downstream of the main supply shutoff and pressurizes water to a usable level when the incoming pressure falls below 20 psi or when a building's height, distance from the main, or fixture count demands more pressure than the utility can reliably deliver. The pump draws from the supply line, compresses the water, and pushes it into the distribution system or into a pressure tank that acts as a buffer.

In the field, you'll install these in high-rise buildings, rural properties far from the main, or where municipal pressure chronically dips during business hours. They're sized by flow demand and required outlet pressure—typically bringing supply up to 60–80 psi. A pressure tank or check valve downstream prevents the pump from short-cycling and hammering the line. You'll also run a low-pressure cutoff switch so the pump doesn't suck air when the inlet pressure drops too far.

Key concern: a booster pump can't create pressure from nothing. If the main is dead, it draws nothing and fails silently. Always verify adequate inlet pressure before blaming the pump, and confirm the building code allows boosting—some jurisdictions require the utility's written approval or mandate reduced-pressure backflow protection when you boost the supply.