{"product_id":"tempstar-40va-transformer-for-t8mpl100f20b1-115v-to-24v-ships-today","title":"Tempstar 40VA Transformer for T8MPL100F20B1 — 115V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM 40VA control transformer (OEM Part #1172810) powers the 24V control circuit of the Tempstar T8MPL100F20B1 gas furnace. It steps line voltage of 115V down to 24V, supplying the thermostat, gas valve, ignition control board, and relays. A failed transformer is one of the most common causes of a completely dead furnace — no thermostat display, no ignition sequence, and no blower. Symptoms include a blown low-voltage fuse, a burnt smell at the control board, or zero volts measured across the secondary 'R' and 'C' terminals.\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\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\u003ctr\u003e\n\u003ctd\u003eFit\u003c\/td\u003e\n\u003ctd\u003eOEM Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDesigned for the Tempstar T8MPL100F20B1 furnace and compatible ICP\/Heil\/Comfortmaker furnaces using a 40VA 115V-to-24V control transformer. Verify primary voltage tap and VA rating against the unit you are servicing.\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 service switch and verify zero voltage with a multimeter.\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 wire connection before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the leads, then unbolt the failed transformer from its bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect primary (line) and secondary (24V) leads 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 a normal call-for-heat sequence.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eFurnace completely dead — no thermostat power\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown 3A low-voltage control fuse\u003c\/li\u003e\n\u003cli\u003eZero or low voltage measured on the 24V secondary\u003c\/li\u003e\n\u003cli\u003eBurnt smell or discoloration at the transformer\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":63021776896371,"sku":"1172810-GEN","price":27.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048403157363,"sku":"1172810","price":36.34,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1172810_5334a773-5288-4ea1-87c9-4dfbf42452c5.jpg?v=1782958262","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-t8mpl100f20b1-115v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}