{"product_id":"tempstar-40va-transformer-for-thb07k34rta-208-240v-to-24v-ships-today","title":"Tempstar 40VA Transformer for THB07K34RTA — 208\/240V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM 40VA control transformer (OEM 1056899) steps line voltage of 208\/240V down to the 24V Class 2 control circuit used throughout the Tempstar THB07K34RTA PTAC unit. The listing also covers the unit's 24V control relays — a single-throw relay (OEM 1053004) and a DPST relay (OEM 1060940) — that switch the compressor and fan loads. When a control transformer fails, the entire 24V circuit goes dead: the thermostat is unresponsive, relays won't pull in, and nothing energizes even though line voltage is present. A buzzing, blackened, or open-winding transformer is a clear replacement candidate.\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\u003eOEM Part Numbers\u003c\/td\u003e\n\u003ctd\u003e1056899 (Transformer), 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 \/ 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\u003e208\/240V\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\u003eTHB07K34RTA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect OEM replacement for the Tempstar \/ ICP \/ Heil THB07K34RTA PTAC control circuit. The 40VA transformer and matching 24V relays are the original control components for this model.\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 breaker and verify zero voltage with a multimeter on both primary and secondary leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the PTAC cabinet cover to reach the control panel and transformer bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the primary and secondary wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unscrew the transformer from its bracket and disconnect the 208\/240V primary and 24V secondary leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect primary and secondary per your photo, and confirm relay wiring.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify 24V at the secondary and that the relays energize.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo 24V control power; thermostat and relays completely dead.\u003c\/li\u003e\n\u003cli\u003eAudible buzzing or humming from the transformer.\u003c\/li\u003e\n\u003cli\u003eScorched, discolored, or melted transformer housing.\u003c\/li\u003e\n\u003cli\u003eOpen or shorted winding read on a multimeter.\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":63021639172467,"sku":"1053004-GEN","price":34.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048412299635,"sku":"1053004","price":44.2,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1053004_56752e53-94e9-4b5f-bb4a-23919a93fff2.jpg?v=1782958588","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-thb07k34rta-208-240v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}