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the internal snap disc has failed and the replacement limit switch is required
While some mounting brackets are adjustable
Optimized Performance: Maintains the internal pressure required for efficient fuel-to-air ratios and peak boiler efficiency
For systems exceeding these pressure requirements
Operating at 6 Watts
McDonnell & Miller 51-2-HD Control Freon the internal snap disc hasThe McDonnell & Miller 51 2 HD is a heavy duty head mechanism only (Part Number 135100) designed specifically for field replacement on Series 51 2 mechanical water feeders. This unit is engineered for low pressure steam and hot water boiler applications, supporting systems with a maximum vessel pressure of 35 PSI. As a specialized low water cut off (LWCO) component, it features a snap acting SPDT switch that provides simultaneous feed control and