{"product_id":"18557-2-aerco-boiler-and-water-heater-20-240f-rev-act-remote-bulb","title":"18557-2  AERCO Boiler and Water Heater -20\/240F REV ACT REMOTE BULB","description":"\u003ch2\u003e18557-2 AERCO Boiler and Water Heater -20\/240F REV ACT REMOTE BULB\u003c\/h2\u003e\n\u003cp\u003e\u003cspan style=\"background-color: rgb(255, 255, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: large; background-color: rgb(255, 255, 0);\"\u003eNormal Stocking Item in Our Warehouse \u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eAERCO 18557‑2 is the OEM –20°F to 240°F Reverse‑Acting Remote Bulb Temperature Control\u003c\/strong\u003e, and the grounded search results give us a complete, authoritative profile of the part. \u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv class=\"relative pb-6 w-full after:border-b after:border-stroke-300 after:w-full after:absolute after:mt-3\"\u003eAERCO 18557‑2 Remote Bulb Temperature Control (–20°F to 240°F, Reverse‑Acting) — OEM hydronic temperature controller for AERCO boilers and water heaters. Features a remote bulb sensor for accurate temperature monitoring and reverse‑acting operation for high‑limit and safety applications. Engineered for precise, reliable performance in commercial HVAC and hydronic systems.\u003c\/div\u003e\n\u003ch2\u003e🔧 \u003cstrong\u003eCore Identity \u0026amp; Function\u003c\/strong\u003e\n\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 18557‑2 \u003cstrong\u003eComponent:\u003c\/strong\u003e Reverse‑Acting Remote Bulb Temperature Control \u003cstrong\u003eOEM:\u003c\/strong\u003e AERCO \u003cstrong\u003eTemperature Range:\u003c\/strong\u003e \u003cstrong\u003e–20°F to 240°F\u003c\/strong\u003e \u003cstrong\u003eAction:\u003c\/strong\u003e \u003cstrong\u003eReverse‑acting\u003c\/strong\u003e (output decreases as sensed temperature rises)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis control uses a \u003cstrong\u003eremote bulb sensor\u003c\/strong\u003e to monitor temperature at a distance from the control body (pipe, tank, duct, or heat‑exchanger surface). The reverse‑acting design is used when \u003cstrong\u003erising temperature must reduce output\u003c\/strong\u003e, such as:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul role=\"list\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eHigh‑limit safety functions\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCooling‑valve actuation\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eHydronic system protection\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCombustion‑air or water‑temperature regulation\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul role=\"list\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTemperature Range:\u003c\/strong\u003e –20°F to 240°F\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eAction Type:\u003c\/strong\u003e Reverse‑acting\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eSensor Type:\u003c\/strong\u003e Remote bulb\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eApplication:\u003c\/strong\u003e Boiler control, commercial HVAC, hydronic heating\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eOperation:\u003c\/strong\u003e Output decreases as sensed temperature rises\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eMounting:\u003c\/strong\u003e Bulb installs in process; control mounts remotely\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eApplications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eUsed in:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul role=\"list\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAERCO commercial boilers\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAERCO commercial water heaters\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eHydronic heating systems requiring remote temperature sensing\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eHigh‑limit or reverse‑acting control loops\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eTypical replacement scenarios:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul role=\"list\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eFaulty or drifting temperature control\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eHigh‑limit safety failures\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eRemote bulb leakage or sensor failure\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003ePreventive maintenance on aging control assemblies\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"Neuco","offers":[{"title":"Default Title","offer_id":45558659481666,"sku":"18557-2","price":5304.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1071\/8320\/files\/Screenshot2025-09-11195035.png?v=1757645461","url":"https:\/\/hvacpartstore.com\/products\/18557-2-aerco-boiler-and-water-heater-20-240f-rev-act-remote-bulb","provider":"HVACpartstore","version":"1.0","type":"link"}