As a direct HVAC replacement part

This is a low pressure cut-out switch

As a 5th-generation ZPK5 model

Note for California residents:

Weil McLain 511-624-512 Pressure Switch Els PW 17895 As a direct HVAC replacementThe Weil McLain 511 624 512 Pressure Switch is a critical safety component designed specifically for HE and HE II Series 3 boilers (sizes 3, 4, and 5). Engineered as a SPDT (Single Pole Double Throw) differential switch, this part is factory calibrated to a 0. 80" WC (Water Column) setpoint. Its primary function is to prove the induced draft fan is moving sufficient air to vent combustion gases safely. If the inducer motor fails to pull a vacuum