{"product_id":"icp-40va-transformer-for-x8mpt125j20a1-115v-to-24v-oem-control-transformer-ships-today-1","title":"ICP 40VA Transformer for X8MPT125J20A1 — 115V to 24V OEM Control Transformer | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM control transformer (part #1012722) steps your incoming 115V line voltage down to the 24V control voltage that runs the thermostat, gas valve, control board relays, and safety circuits on your ICP \/ Tempstar \/ Heil X8MPT125J20A1 furnace. Rated at 40VA, it supplies enough current for the full low-voltage load of a two-stage furnace plus a typical thermostat and condensing unit contactor. When a transformer fails — usually from a shorted thermostat wire, a stuck contactor drawing excess current, or simple age — the entire 24V control system goes dead: no display on the thermostat, no response to a heat or cool call, and no clicking from the gas valve or relays. This direct-fit OEM transformer restores 24V control power without the guesswork of universal substitutes.\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\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1012722 (TRANS 115\u0026gt;24 40VA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eControl \/ step-down 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\u003e115 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Voltage\u003c\/td\u003e\n\u003ctd\u003e24 VAC\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\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eBuilt for the ICP-family X8MPT125J20A1 two-stage furnace and the matching Tempstar, Heil, Comfortmaker, and Day \u0026amp; Night control systems that use a 115V-to-24V 40VA transformer. Verify your primary line voltage is 115V and that your existing transformer is rated 40VA before ordering.\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 breaker and verify zero voltage with a multimeter at both the line and control terminals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace control-compartment service panel to expose the transformer and control board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every primary (line) and secondary (24V) lead and terminal before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the primary and secondary leads, then unbolt the transformer from its mounting bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect the 115V leads to the primary and the 24V leads to the secondary exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24VAC across the secondary terminals, then run a heat and cool call to verify the thermostat and controls respond.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eThermostat screen is blank and the furnace won't respond to any call.\u003c\/li\u003e\n\u003cli\u003eNo 24VAC reading across the transformer secondary terminals.\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visibly scorched\/melted transformer housing.\u003c\/li\u003e\n\u003cli\u003eBlown low-voltage fuse on the control board that re-blows immediately.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\u003cp\u003eShips same day on orders placed before 3 PM CST. 30-day returns on unused parts. Backed by the National HVAC Parts fitment guarantee — if it doesn't fit your X8MPT125J20A1, we make it right.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63027200295283,"sku":"1012722","price":36.4,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047398654323,"sku":"1012722-GEN","price":28.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1012722_b91da3c7-b4b6-4ad6-9e9b-c0a690583e65.jpg?v=1782883577","url":"https:\/\/nationalhvacparts.com\/products\/icp-40va-transformer-for-x8mpt125j20a1-115v-to-24v-oem-control-transformer-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}