{"product_id":"tempstar-control-transformer-for-tde125j20g1-40va-115v-to-24v-ships-today","title":"Tempstar Control Transformer for TDE125J20G1 — 40VA 115V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM Tempstar control transformer (part #1012722) steps 115V line voltage down to 24V to power the low-voltage control circuit of your furnace or air handler. Rated at 40VA, it supplies the thermostat, gas valve, relays, and control board. When a transformer fails, the entire 24V control system goes dead — the thermostat screen goes blank, the furnace won't fire, and you may smell a burnt or acrid odor near the control box. A buzzing transformer or a tripped low-voltage fuse on the board are also common warning signs of a failing unit.\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\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\u003e40VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eEngineered as a direct OEM replacement for the Tempstar TDE125J20G1 gas furnace. Also fits many Heil, Comfortmaker, and ICP-family units that use the 1012722 transformer. Always verify the part number on your existing transformer before ordering.\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 breaker and verify zero voltage at the unit with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace control panel to expose the transformer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the primary and secondary wiring 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 bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer and reconnect each lead exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary terminals and normal control operation.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eBlank thermostat and dead 24V control circuit\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown low-voltage control board fuse\u003c\/li\u003e\n\u003cli\u003eAudible buzzing or humming from the transformer\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visible scorching on the windings\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":63021648380275,"sku":"1012722-GEN","price":24.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048438055283,"sku":"1012722","price":32.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1012722_d2ca2ed2-4bdb-4691-8aff-3742d48835af.jpg?v=1782959598","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-control-transformer-for-tde125j20g1-40va-115v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}