operating via system power (24VAC) or battery backup using two AA alkaline batteries

this unit provides the reliable SPST (Single Pole Single Throw) switching necessary for critical limit sensing and temperature differential management in both residential and light commercial systems

it fits specific 10x10

For higher temperature needs

McDonnell & Miller 51-2 Feeder Els PW 17895 operating via system power (24VAC)The McDonnell & Miller 51 2 (Part Number 135000) is a heavy duty mechanical water feeder and low water cut off (LWCO) designed for industrial and commercial low pressure steam and hot water boilers. Engineered for systems with a capacity exceeding 5,000 sq. ft., this unit provides critical protection by maintaining a consistent minimum safe water level regardless of electrical status. It features 1" NPT female connections and a snap acting SPDT switch