ensuring the gas valve remains closed if a flame is not detected during the ignition sequence

this valve facilitates the continuous purging of air from hot or cold water distribution lines

this T-O-D style (Therm-O-Disc) component integrates a manual reset high limit set at 170°F to prevent over-temperature conditions

Applying 120V will cause immediate failure and potential damage to the control board

and T51000 series mechanical time switches

McDonnell & Miller 310437 Float and Gasket 30067439-890 ensuring the gas valve remainsThe McDonnell & Miller 310437 (Model Number FLT 51 05) is a high precision replacement float and gasket kit engineered specifically for the Series 51 and Series 551 S mechanical water feeders. This kit is a critical component for maintaining the integrity of low water cut off (LWCO) systems and ensuring accurate boiler water level control. Featuring a durable stainless steel float and a high performance F 26 gasket (304200), this assembly is designed