{"product_id":"tempstar-control-transformer-for-t9uhx080j12a2-40va-115v-to-24v-ships-today","title":"Tempstar Control Transformer for T9UHX080J12A2 — 40VA 115V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis is the OEM low-voltage control transformer (OEM part 1172810) for the Tempstar T9UHX080J12A2 gas furnace. The transformer steps down 115V line voltage to the 24V control voltage that powers the thermostat, control board, gas valve, igniter circuit, and relays. Rated at 40VA, it supplies enough current to run the entire low-voltage control circuit. When a transformer fails, the furnace goes completely dead — no thermostat display, no blower, no ignition — even though line power is present. Symptoms include a blown low-voltage fuse, a buzzing or scorched transformer, or an open primary\/secondary winding when checked with a multimeter.\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\u003e1172810\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eControl Transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar\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\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDesigned as a direct-fit replacement for the Tempstar T9UHX080J12A2 furnace and compatible ICP\/Heil\/Comfortmaker variants that use the 1172810 transformer. Always match the VA rating and primary\/secondary voltages to your original 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 furnace switch and breaker, then verify zero voltage at the transformer leads with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace blower\/control compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary and secondary wire connections before disconnecting anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the 115V primary leads and the 24V 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, then reconnect the primary and secondary wiring exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V on the secondary and normal thermostat operation.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eFurnace is completely unresponsive with no 24V control power present.\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown low-voltage control fuse.\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, buzzing, or has a burnt smell.\u003c\/li\u003e\n\u003cli\u003eMultimeter shows an open or shorted primary\/secondary winding.\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":63021677019507,"sku":"1172810-GEN","price":28.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048437956979,"sku":"1172810","price":37.63,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1172810_e5ddf860-8a2d-451a-8c89-78cf9a4e52df.jpg?v=1782959593","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-control-transformer-for-t9uhx080j12a2-40va-115v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}