{"product_id":"mcdonnell-miller-173003-150s-hd-head-mechanism-only","title":"McDonnell \u0026 Miller 173003 150S-HD Head Mechanism Only","description":"\u003cp\u003eMaintain precise water level control in your commercial steam boiler with the \u003cstrong\u003e173003\u003c\/strong\u003e replacement head mechanism. Engineered specifically for the \u003cstrong\u003e150S-HD\u003c\/strong\u003e series, this component provides a streamlined solution for servicing existing low-water cut-off and pump control units without requiring a complete piping overhaul.\u003c\/p\u003e\u003cp\u003eThe head mechanism functions as the primary sensing and switching interface, utilizing a high-performance internal linkage to translate float position into reliable electrical signals. By replacing the head assembly, you ensure that the internal switches and contacts remain responsive to fluctuations in boiler water levels, effectively preventing dry-firing and maintaining consistent operational safety.\u003c\/p\u003e\u003ch4\u003eKey System Performance Baselines:\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Switching:\u003c\/strong\u003e Maintains accurate control over feed pump activation and burner cut-off setpoints.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRugged Construction:\u003c\/strong\u003e Built to withstand the high-temperature and high-pressure demands of commercial steam heating environments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStreamlined Installation:\u003c\/strong\u003e Allows for quick component-level servicing, reducing system downtime during routine maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e⚠️ \u003cstrong\u003eApplication Profile:\u003c\/strong\u003e Primarily used in commercial and industrial steam boiler installations where McDonnell \u0026amp; Miller 150S-HD units are employed for automatic water level regulation and low-water cut-off protection.\u003c\/p\u003e","brand":"McDonnell \u0026 Miller","offers":[{"title":"Default Title","offer_id":43126172352606,"sku":"173003","price":1110.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/173003_image_65f6f5b8-a1b8-4915-8321-adc4fc6fd1e1.png?v=1786046424","url":"https:\/\/nationalboilersupply.com\/products\/mcdonnell-miller-173003-150s-hd-head-mechanism-only","provider":"National Boiler Supply","version":"1.0","type":"link"}