{"product_id":"icp-transformer-for-wfmr090b042b2-40va-120-24v-ships-today","title":"ICP Transformer for WFMR090B042B2 — 40VA 120\/24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM 40VA step-down transformer (OEM 1177217) supplies the 24-volt control power for the ICP\/Tempstar\/Heil WFMR090B042B2 furnace. It converts incoming 120V line voltage to the 24V that runs the thermostat, control board, gas valve, and relays. When a transformer fails — often from a shorted control wire or stuck contactor — the entire low-voltage circuit goes dead: the thermostat is blank, the furnace won't start, and nothing responds to a heat call. A 40VA rating provides enough capacity for the furnace's control load with margin. Replacing a blown transformer restores 24V power and brings the control system back online.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOEM Part Number\u003c\/td\u003e\n\u003ctd\u003e1177217\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eStep-Down Control Transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40 VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e120V Primary \/ 24V Secondary\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Tempstar \/ Heil\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eWFMR090B042B2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eFurnace 24V Control Circuit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDesigned for the ICP-family WFMR090B042B2 furnace and interchangeable across the Tempstar, Heil, and Comfortmaker models that use a 40VA 120-24V control transformer. Confirm the primary\/secondary voltages and VA rating against your existing transformer before installing.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the furnace switch and breaker; verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace control-compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the primary (line) and secondary (24V) wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads, remove the transformer mounting screws, and lift out the failed unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, connect 120V to the primary and 24V to the secondary per your photo, and check for any shorted control wire that caused the original failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary, then verify the thermostat and furnace respond to a heat call.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBlank thermostat and dead low-voltage controls\u003c\/li\u003e\n\u003cli\u003eFurnace gets line power but won't start\u003c\/li\u003e\n\u003cli\u003eNo 24V reading across the transformer secondary\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, buzzing, or smells burnt\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63021567082867,"sku":"1177217","price":37.7,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047743340915,"sku":"1177217-GEN","price":29.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1177217_f7cd4e41-5a3d-4081-8274-98db5c721198.jpg?v=1782896551","url":"https:\/\/nationalhvacparts.com\/products\/icp-transformer-for-wfmr090b042b2-40va-120-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}