This thermostat is designed specifically for 1-heat/1-cool systems

As a 5th-generation ZPK5 model

System Safety: Prevents furnace operation if the inducer motor fails or the venting system is restricted

Dual-Thread Design: Features 5/16-18 and 3/8-16 NPT threaded ends for seamless integration between the valve body and the float

This is a low pressure cut-out switch

Weil McLain 511-624-512 Pressure Switch Els PW 17895 This thermostat is designed specificallyThe 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