{"product_id":"mcdonnell-miller-135100-51-2-hd-head-mechanism-for-water-feeder","title":"McDonnell \u0026 Miller 135100 51-2-HD Head Mechanism for Water Feeder","description":"\u003cp\u003eRestore precise water level control in your steam heating system with the \u003cb\u003eMcDonnell \u0026amp; Miller 135100 51-2-HD\u003c\/b\u003e head mechanism. This essential replacement component acts as the primary sensing and control assembly for compatible mechanical water feeders, ensuring your boiler maintains optimal operating levels to prevent dry firing and potential damage. By utilizing the \u003cb\u003e135100\u003c\/b\u003e assembly, you ensure that your system remains compliant with original equipment specifications and safety standards.\u003c\/p\u003e\u003cp\u003eThe mechanism functions by utilizing a float-operated linkage that monitors the water line within the boiler. As the water level drops, the mechanical action of the float triggers the feeder valve to introduce makeup water, effectively maintaining a consistent, safe volume. This direct-acting design provides high reliability in demanding hydronic environments, reducing the need for complex electronic controls while maximizing service life.\u003c\/p\u003e\u003ch4\u003eKey System Performance Baselines:\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003ePrecision Level Sensing:\u003c\/b\u003e Calibrated for consistent water line maintenance within the boiler vessel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eMechanical Reliability:\u003c\/b\u003e Built with heavy-duty components to withstand the cyclic demands of steam systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eStreamlined Installation:\u003c\/b\u003e Engineered for a direct fitment, reducing downtime during critical maintenance cycles.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e⚠️ \u003cstrong\u003eApplication Profile:\u003c\/strong\u003e Recommended for use in commercial and residential steam boiler applications requiring automatic makeup water feed control. Must be installed by a qualified hydronic technician to ensure proper float clearance and seat alignment.\u003c\/p\u003e","brand":"McDonnell \u0026 Miller","offers":[{"title":"Default Title","offer_id":43125817213022,"sku":"135100","price":1471.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/135100_image_b5d6e22f-1378-4669-8c2d-8bbbf38a79a0.png?v=1786038485","url":"https:\/\/nationalboilersupply.com\/products\/mcdonnell-miller-135100-51-2-hd-head-mechanism-for-water-feeder","provider":"National Boiler Supply","version":"1.0","type":"link"}