{"product_id":"icp-40va-transformer-for-wfmr135d066b3-120v-to-24v-oem-1177217-ships-today-1","title":"ICP 40VA Transformer for WFMR135D066B3 — 120V to 24V OEM 1177217 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM control transformer (part \u003cstrong\u003e1177217\u003c\/strong\u003e) supplies the 24V control circuit on the ICP \/ Tempstar \/ Heil WFMR135D066B3 furnace. It steps the incoming \u003cstrong\u003e120V\u003c\/strong\u003e line voltage down to \u003cstrong\u003e24V\u003c\/strong\u003e at \u003cstrong\u003e40VA\u003c\/strong\u003e, powering the thermostat, gas valve, control board relays, and safety circuits. When a transformer fails — usually from a shorted thermostat wire, a stuck contactor, or simple age — the entire low-voltage system goes dead: no thermostat display, no call for heat or cool, and no response from the equipment. A blown internal fuse link or burnt windings is a common no-power diagnosis. Installing the correct 40VA OEM transformer restores stable control voltage to the whole system.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\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\u003ePart 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\u003eControl \/ Class 2 Transformer\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\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40 VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Voltage\u003c\/td\u003e\n\u003ctd\u003e120V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Voltage\u003c\/td\u003e\n\u003ctd\u003e24V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eWFMR135D066B3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Direct Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect-fit replacement for the ICP-family WFMR135D066B3 furnace and the shared Tempstar, Heil, and Comfortmaker units that use a 40VA 120-to-24V control transformer. Verify your primary voltage is 120V before installing.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\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 on both primary and secondary leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace service\/control panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every primary and secondary wire and its terminal before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads, unscrew the transformer from the mounting bracket or control panel, and lift it out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect the 120V primary and 24V secondary leads exactly per your photo, and ensure terminals are tight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary, a live thermostat, and a normal heat call.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eThermostat is blank and the system is completely unresponsive.\u003c\/li\u003e\n\u003cli\u003eNo 24V measured across the secondary terminals.\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, humming loudly, or smells burnt.\u003c\/li\u003e\n\u003cli\u003eRepeated control-fuse failures pointing to a shorted or failing transformer.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day on orders placed before 3 PM CST. 30-day hassle-free returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63027237454195,"sku":"1177217","price":35.04,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047380730227,"sku":"1177217-GEN","price":26.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1177217_7eef133c-b30e-41fb-88a3-23ddb0add4bc.jpg?v=1782882822","url":"https:\/\/nationalhvacparts.com\/products\/icp-40va-transformer-for-wfmr135d066b3-120v-to-24v-oem-1177217-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}