{"product_id":"pentairwaterpoolandspainc_475978","title":"Pentair Fan Control Board | ETi® 400 Heater | 475978","description":"\u003cp\u003eThe Pentair Fan Control Board (475978) is the OEM replacement control board for the ETi® 400 Heater, managing fan operation to maintain safe and efficient heat exchange performance.\u003c\/p\u003e\n\n\u003cp style=\"background-color: #fff3cd; border: 2px solid #FFEAA7; padding: 15px; border-radius: 5px; margin: 15px 0; color: #856404;\"\u003e\n\u003cstrong\u003e⚠️ IMPORTANT: LICENSED PROFESSIONAL INSTALLATION REQUIRED\u003c\/strong\u003e\u003cbr\u003e\nGas and electrical heater components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service gas or high-voltage components without proper certification.\n\u003c\/p\u003e\n\n\u003cp\u003eThe fan control board governs the operation of the ETi® 400's combustion fan assembly. When this board fails, the heater may not ignite, may shut down on fault codes, or may run the fan erratically — all of which interrupt heating cycles. Replacing this board with the OEM part restores correct fan sequencing and ensures the heater's safety interlocks function as designed.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePentair Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e475978\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePart Name\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eFan Control Board\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eQuantity Included\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eEach\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eFits Into\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eEquipment Line\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eModel \/ Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eNotes\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003ePentair\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eETi® 400 Heater — ETi Series\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eETi400\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cem\u003eCompatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003ePro Tip\u003c\/h3\u003e\n\u003cp\u003eBefore ordering, locate the part number printed on your existing control board and confirm it matches 475978. Control board variants can differ by heater revision, and installing an incorrect board may cause fault codes or prevent ignition. If your ETi® 400 is displaying a fan-related fault code, also inspect the fan motor and wiring harness — a failed board and a failed motor can present with identical symptoms, and confirming the fault source before replacing the board avoids an unnecessary part swap.\u003c\/p\u003e\n\n\u003c!-- wft:processed:manual:2026-04-06 --\u003e","brand":"Pentair","offers":[{"title":"Default Title","offer_id":53971895058707,"sku":"475978","price":151.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0920\/0687\/5411\/files\/pentair-fan-control-board-eti-400-heater-475978-4.webp?v=1779201467","url":"https:\/\/poolaroo.com\/products\/pentairwaterpoolandspainc_475978","provider":"Poolaroo","version":"1.0","type":"link"}