{"product_id":"tempstar-40va-transformer-for-t9mpd050f12a3-115v-to-24v-oem-ships-today","title":"Tempstar 40VA Transformer for T9MPD050F12A3 — 115V to 24V OEM | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM control transformer, OEM part number \u003cstrong\u003e1012722\u003c\/strong\u003e, steps 115V line voltage down to 24V to power the low-voltage control circuit of the Tempstar T9MPD050F12A3 gas furnace. Rated at 40VA, it supplies the thermostat, control board, gas valve, and relays. When a transformer fails — usually from a shorted control wire or a stuck gas valve drawing excess current — the entire 24V circuit goes dead: no thermostat display, no blower, no heat. A correctly sized 40VA transformer restores reliable control power.\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\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\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\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40 VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM\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 Tempstar T9MPD050F12A3 furnace and shared across many ICP \/ Heil \/ Tempstar \/ Comfortmaker furnaces using a 115V-to-24V 40VA control transformer. Verify primary voltage and lead\/terminal configuration 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 switch and breaker; 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 — Photo all primary and secondary wire connections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads, remove the mounting screws, and take out the failed transformer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer and reconnect 115V primary and 24V secondary leads exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V at the secondary and normal control operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eNo 24V control power; thermostat is blank\u003c\/li\u003e\n\u003cli\u003eFurnace completely unresponsive to a heat call\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visible scorching on the transformer\u003c\/li\u003e\n\u003cli\u003eNo measurable voltage at the secondary terminals\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":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021684490611,"sku":"1012722-GEN","price":28.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048406368627,"sku":"1012722","price":36.4,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1012722_0b37d8c6-6aea-451d-9ae9-ee9feb75fd31.jpg?v=1782958366","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-t9mpd050f12a3-115v-to-24v-oem-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}