{"product_id":"tempstar-40va-transformer-for-tca948gka100-208-230v-to-24v-ships-today","title":"Tempstar 40VA Transformer for TCA948GKA100 — 208\/230V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM control transformer (part number 1170676) steps line voltage down from 208\/230V to 24V and is rated at 40VA for the Tempstar TCA948GKA100 unit. The transformer is the heart of the low-voltage control circuit — it powers the thermostat, contactor coil, relays, and safety switches. When a transformer fails (often from a control short or surge), the entire 24V system goes dead: the thermostat blanks, the contactor will not pull in, and the system cannot start. The 40VA rating provides enough capacity for the standard control load with margin for accessories. Replacing the failed transformer restores full control power and reliable operation.\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\u003e1170676\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\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Voltage\u003c\/td\u003e\n\u003ctd\u003e208\/230V\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\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eTCA948GKA100\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 TCA948GKA100 and equivalent ICP-family units (Heil, Comfortmaker, Arcoaire) using a 40VA 208\/230V-to-24V transformer. Confirm VA rating and primary\/secondary voltages against your original.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the electrical access panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photo all primary and secondary leads before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the line-voltage primary leads and the 24V secondary leads, then unbolt the old transformer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, matching the correct primary tap (208 vs 230V), and reconnect per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V at the secondary and proper control operation.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eThermostat is blank and the system is completely dead at low voltage.\u003c\/li\u003e\n\u003cli\u003eNo 24V reading across the secondary terminals.\u003c\/li\u003e\n\u003cli\u003eContactor and relays will not energize.\u003c\/li\u003e\n\u003cli\u003eBurned smell or visibly scorched transformer body.\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":63021660242291,"sku":"1170676-GEN","price":28.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048409186675,"sku":"1170676","price":37.63,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1170676_f7670e2c-05a6-47ca-822f-839bdfce934d.jpg?v=1782958478","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-tca948gka100-208-230v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}