{"product_id":"tempstar-40va-transformer-for-thb09r25rta-277v-to-24v-control-ships-today","title":"Tempstar 40VA Transformer for THB09R25RTA — 277V to 24V Control | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM 40VA control transformer steps 277V line power down to the 24V the control circuit needs on the Tempstar THB09R25RTA. The primary part (OEM 1091226, TRANS 277\u0026gt;24 40VA) powers the thermostat, relays, and contactor coils; the kit also covers the 24V control relays used in this circuit (OEM 1053004 SPST and 1060940 DPST). A failed transformer is one of the most common no-power, no-response faults — when it opens, the unit goes completely dead even though line voltage is present. Replacing it with the factory 40VA part restores reliable 24V control.\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 Numbers\u003c\/td\u003e\n\u003ctd\u003e1091226 (TRANS), 1053004 (RELAY 24V), 1060940 (RELAY 24V DPST)\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 (Heil \/ ICP family)\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\u003e277V\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\u003eTHB09R25RTA\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\u003eDirect-fit replacement for the Tempstar THB09R25RTA. The 277V-to-24V 40VA transformer and matching 24V relays are common across Heil, ICP, and Comfortmaker equipment running on 277V control. Confirm both your primary voltage (277V) and VA rating before installing.\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 and verify zero voltage with a multimeter; 277V is lethal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the service panel to expose the control compartment.\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 — Disconnect the 277V primary and 24V secondary leads, then unbolt the transformer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, land the 277V primary and 24V secondary per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary and proper control operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eUnit completely dead with confirmed line voltage present.\u003c\/li\u003e\n\u003cli\u003eNo 24V reading across the transformer secondary.\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visibly scorched\/discolored transformer body.\u003c\/li\u003e\n\u003cli\u003eRepeated control fuse blowing or intermittent control dropout.\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":63021638287731,"sku":"1053004-GEN","price":34.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048412692851,"sku":"1053004","price":45.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1053004_82d2b9b5-9b30-472a-88de-736ad8a404f6.jpg?v=1782958600","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-thb09r25rta-277v-to-24v-control-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}