{"product_id":"tempstar-40va-transformer-for-t8mpn150j20a1-115v-to-24v-control-ships-today","title":"Tempstar 40VA Transformer for T8MPN150J20A1 — 115V to 24V Control | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM 40VA control transformer (part #1012722) powers the 24-volt control circuit on the Tempstar T8MPN150J20A1 gas furnace. It steps line voltage of 115V down to 24V to drive the control board, gas valve, thermostat, and relays. A failed transformer is one of the most common reasons a furnace goes completely dead: no thermostat display, no control-board lights, and no call for heat. Transformers fail from age, a shorted low-voltage circuit, or a stuck contactor that overdraws the secondary winding. This 40VA unit delivers ample capacity for the furnace's 24V loads with margin for a wired-in accessory such as a humidifier or condensate switch.\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\u003eDescription\u003c\/td\u003e\n\u003ctd\u003eTransformer 115V to 24V, 40VA\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\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eBuilt for the Tempstar T8MPN150J20A1 furnace and compatible with many ICP-manufactured Tempstar, Heil, Comfortmaker, and Carrier\/Bryant furnaces that use a 115V-to-24V 40VA control transformer. Confirm the primary tap voltage and mounting bracket match your existing unit.\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 and verify zero voltage with a multimeter on both the line and 24V circuits.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace control-compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every primary and secondary lead before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the wires, then unbolt the old transformer from its bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect the 115V primary and 24V secondary leads exactly as photographed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, confirm 24V at the secondary with a meter, and verify the furnace responds to a call for heat.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFurnace is completely dead with a blank thermostat\u003c\/li\u003e\n\u003cli\u003eNo 24V output measured at the transformer secondary\u003c\/li\u003e\n\u003cli\u003eVisible scorching, swelling, or a burnt smell from the transformer\u003c\/li\u003e\n\u003cli\u003eRepeated blown low-voltage fuse after the short is cleared\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":63021748715891,"sku":"1012722-GEN","price":24.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048404861299,"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_d6b35091-ad16-460e-9155-a1b9f98f085b.jpg?v=1782958308","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-t8mpn150j20a1-115v-to-24v-control-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}