{"product_id":"tempstar-40va-transformer-for-thb07k25rta-208-240v-to-24v-ships-today","title":"Tempstar 40VA Transformer for THB07K25RTA — 208\/240V to 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM 40VA control transformer (part 1056899, TRANS 208\/240\u0026gt;24 40VA) steps the high-voltage line down to the 24V control circuit on the Tempstar THB07K25RTA PTAC. This kit also includes the unit's 24V relays — 1053004 (RELAY 24V) and 1060940 (RELAY 24V DPST) — which switch the compressor and heat loads on the low-voltage signal. When the transformer fails, the 24V circuit goes dead: the thermostat won't power up and nothing energizes. A failed relay shows as a contactor or heater that won't pull in even with a good 24V call. These are factory-spec replacements rated to match the original control circuit.\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\u003eTransformer Part Number\u003c\/td\u003e\n\u003ctd\u003e1056899 (TRANS 208\/240\u0026gt;24 40VA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelay Part Numbers\u003c\/td\u003e\n\u003ctd\u003e1053004 (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\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar (Heil \/ ICP)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eTHB07K25RTA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eBuilt for the Tempstar \/ Heil \/ ICP THB07K25RTA PTAC and related THB07K25 series units using the same 40VA 24V control circuit. Match OEM part numbers 1056899, 1053004, and 1060940 against your failed components before ordering.\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.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the PTAC grille and control-box service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary and secondary wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect leads and unbolt the old transformer and relay(s) from the bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer and relay, wiring primary to line and secondary to the 24V circuit per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, confirm 24V at the secondary, and verify the relays pull in on a call.\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 is dead.\u003c\/li\u003e\n\u003cli\u003eBlown low-voltage fuse or burnt\/buzzing transformer.\u003c\/li\u003e\n\u003cli\u003eCompressor or heat relay won't energize on a valid call.\u003c\/li\u003e\n\u003cli\u003eIntermittent operation tied to the control circuit.\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":63021639336307,"sku":"1053004-GEN","price":32.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048412234099,"sku":"1053004","price":42.84,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1053004_9acf7a70-18e0-477e-9714-03e67a9eac87.jpg?v=1782958586","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-thb07k25rta-208-240v-to-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}