{"product_id":"tempstar-40va-transformer-for-t8dnl075f16b1-115v-to-24v-ships-today","title":"Tempstar 40VA Transformer for T8DNL075F16B1 — 115V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM control transformer (part number 1172810, \"TRANS 115\u0026gt;24 40VA\") supplies low-voltage power to the Tempstar T8DNL075F16B1 gas furnace. It steps the incoming 115V line voltage down to 24V at 40VA, energizing the thermostat circuit, gas valve, control board, and relays. When the transformer fails, the entire low-voltage system goes dead: the thermostat screen blanks, the furnace will not respond to a heat call, and nothing on the 24V circuit operates. A failed transformer is often the result of a shorted gas valve, pinched thermostat wire, or control board fault, so inspect the 24V circuit for shorts before installing the replacement.\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\u003e1172810\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\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eFits the Tempstar T8DNL075F16B1 furnace and the broader ICP\/Tempstar\/Heil T8DNL series that uses a 40VA, 115V-to-24V control transformer. Confirm 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 furnace switch and breaker; verify zero voltage with a multimeter on both the 115V and 24V terminals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control\/blower compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary (line) and secondary (24V) wire connections before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads, unfasten the transformer from its mounting bracket, and lift it out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer and reconnect primary and secondary leads exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, confirm ~24V across the secondary terminals, and run a heat cycle.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBlank thermostat \/ no 24V power anywhere\u003c\/li\u003e\n\u003cli\u003eFurnace does not respond to a heat call\u003c\/li\u003e\n\u003cli\u003eNo measurable voltage across the secondary terminals\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, humming loudly, or smells burnt\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":63021779419507,"sku":"1172810-GEN","price":24.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048402010483,"sku":"1172810","price":32.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1172810_ac3daffb-81c0-4569-bd49-ed7b78bad189.jpg?v=1782958221","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-t8dnl075f16b1-115v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}