{"product_id":"weil-mclain-511-624-542","title":"Weil McLain 511-624-542 Pressure Switch","description":"\u003cp\u003eThe \u003cstrong\u003eWeil McLain 511-624-542 Air Pressure Switch\u003c\/strong\u003e is a \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e \u003cstrong\u003eSPDT\u003c\/strong\u003e differential \u003cstrong\u003eair pressure switch\u003c\/strong\u003e for gas-fired \u003cstrong\u003eWeil McLain\u003c\/strong\u003e boilers. It works as the \u003cstrong\u003ecombustion air\u003c\/strong\u003e proving switch: it senses the pressure difference created when the \u003cstrong\u003edraft inducer\u003c\/strong\u003e is running and tells the ignition control that air is actually moving through the burner and vent path before the burner is allowed to light. The switch comes mounted on a \u003cstrong\u003emetal bracket\u003c\/strong\u003e, and its \u003cstrong\u003eset point\u003c\/strong\u003e is \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe manufacturer's own \u003cstrong\u003eCGt\u003c\/strong\u003e manual addendum lists an \u003cstrong\u003eair pressure switch\u003c\/strong\u003e rated \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e under this part number in its replacement parts table, so \u003cstrong\u003e511-624-542\u003c\/strong\u003e is the factory part number and not a universal cross-reference. Set point is the specification that matters most on a switch like this. A switch with a lower \u003cstrong\u003eset point\u003c\/strong\u003e can prove airflow that is weaker than the boiler was designed for, and a switch with a higher \u003cstrong\u003eset point\u003c\/strong\u003e can cause nuisance lockouts, so the replacement should always match the original \u003cstrong\u003eset point\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSPDT\u003c\/strong\u003e means single pole, double throw: a \u003cstrong\u003ecommon terminal\u003c\/strong\u003e that connects to either a \u003cstrong\u003enormally open\u003c\/strong\u003e or a \u003cstrong\u003enormally closed\u003c\/strong\u003e terminal depending on whether the pressure difference has reached the \u003cstrong\u003eset point\u003c\/strong\u003e. Match the wiring terminal for terminal when you swap it in. Never jump out or bypass an \u003cstrong\u003eair pressure switch\u003c\/strong\u003e to get a boiler running. If the switch does not prove, the cause is usually a blocked vent, a blocked or kinked sensing hose, or a \u003cstrong\u003edraft inducer\u003c\/strong\u003e that is not up to speed, and those are the items to check first.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eKey Benefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFactory 1.53 Inch W.C. Set Point:\u003c\/strong\u003e Matches the \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e \u003cstrong\u003eair pressure switch\u003c\/strong\u003e \u003cstrong\u003eWeil McLain\u003c\/strong\u003e lists in its \u003cstrong\u003eCGt\u003c\/strong\u003e manual addendum, so the proving point is the one the boiler control expects.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSPDT Contact Arrangement:\u003c\/strong\u003e One \u003cstrong\u003ecommon terminal\u003c\/strong\u003e with \u003cstrong\u003enormally open\u003c\/strong\u003e and \u003cstrong\u003enormally closed\u003c\/strong\u003e positions gives the control the signal it needs to confirm airflow before ignition.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBracket Mounted:\u003c\/strong\u003e Arrives on a \u003cstrong\u003emetal bracket\u003c\/strong\u003e, so it mounts the way the original did instead of needing a separate bracket sourced on the side.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e \u003cstrong\u003e511-624-542\u003c\/strong\u003e is the number shown in the \u003cstrong\u003eWeil McLain\u003c\/strong\u003e \u003cstrong\u003eCGt\u003c\/strong\u003e manual addendum for the \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e switch, which takes the guesswork out of ordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCommon Questions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWhat set point does the 511-624-542 have?\u003c\/strong\u003e It is a \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e \u003cstrong\u003eair pressure switch\u003c\/strong\u003e with \u003cstrong\u003eSPDT\u003c\/strong\u003e contacts. Do not substitute a switch with a different \u003cstrong\u003eset point\u003c\/strong\u003e.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWhich boiler does it fit?\u003c\/strong\u003e \u003cstrong\u003eWeil McLain\u003c\/strong\u003e's \u003cstrong\u003eCGt\u003c\/strong\u003e manual addendum lists the \u003cstrong\u003e1.53 inch W.C.\u003c\/strong\u003e \u003cstrong\u003eair pressure switch\u003c\/strong\u003e as \u003cstrong\u003e511-624-542\u003c\/strong\u003e. The addendum does not break the table out by size, so please send us the boiler model and serial number and our team will confirm fit before you buy.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCan I bypass the switch to test the boiler?\u003c\/strong\u003e No. The \u003cstrong\u003eair pressure switch\u003c\/strong\u003e is a safety device that proves venting and combustion airflow. If it is not closing, check the vent, the sensing hoses and the \u003cstrong\u003edraft inducer\u003c\/strong\u003e rather than jumping the switch.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eDisclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.\u003c\/p\u003e\n","brand":"Weil McLain","offers":[{"title":"Default Title","offer_id":68008918220978,"sku":"511-624-542","price":87.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1838\/2375\/files\/511-624-542.jpg?v=1794512964","url":"https:\/\/www.gsistore.com\/en-ca\/products\/weil-mclain-511-624-542","provider":"GSIstore","version":"1.0","type":"link"}