{"product_id":"tempstar-40va-transformer-115v-to-24v-for-t8mpn100j20a1-oem-1012722-ships-today","title":"Tempstar 40VA Transformer 115V to 24V for T8MPN100J20A1 — OEM 1012722 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM control transformer (part number 1012722, TRANS 115\u0026gt;24 40VA) steps the 115V line voltage in the Tempstar T8MPN100J20A1 down to the 24V needed by the thermostat, gas valve, and control board. Rated at 40VA, it supplies the low-voltage control circuit that runs the entire heating sequence. A failed transformer means a completely dead control board — no thermostat response, no ignition, no blower. It is a common failure after a control-circuit short or a power surge.\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\u003e1012722\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar (ICP \/ 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\u003e115V\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\u003eFit\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 Tempstar T8MPN100J20A1 and other ICP\/Heil\/Comfortmaker furnaces using the 1012722 40VA 115-to-24V transformer. Verify primary voltage and VA rating against your existing unit 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 switch and breaker and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary (line) and secondary (24V) wire connections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the leads, then unbolt the old transformer from the cabinet.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect primary and secondary leads per your photo, and confirm the ground.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and measure 24V across the secondary terminals to confirm output.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo 24V at the control board or thermostat.\u003c\/li\u003e\n\u003cli\u003eFurnace completely unresponsive to the thermostat.\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, swollen, or smells burnt.\u003c\/li\u003e\n\u003cli\u003eRepeated blown control-circuit fuse after a short.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021765132659,"sku":"1012722-GEN","price":26.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048401224051,"sku":"1012722","price":35.04,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1012722_31464f24-e83c-481e-bfb1-98b89a10152e.jpg?v=1782958189","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-115v-to-24v-for-t8mpn100j20a1-oem-1012722-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}