{"product_id":"tempstar-40va-transformer-for-teb12k25rta-208-240v-to-24v-with-relays-ships-today","title":"Tempstar 40VA Transformer for TEB12K25RTA — 208\/240V to 24V with Relays | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis is the genuine OEM 40VA control transformer (OEM 1056899) for the Tempstar TEB12K25RTA PTAC, supplied with its companion 24V control relays (OEM 1053004, single relay; OEM 1060940, 24V DPST relay). The transformer steps the line-voltage 208\/240V supply down to the 24V control voltage that powers the thermostat, relays, and switching circuit. When a control transformer fails — often from a shorted secondary or an overloaded class-2 circuit — the entire low-voltage control system goes dead: no cooling, no heating, and an unresponsive thermostat even though line power is present. The included relays handle the actual switching of the heating and cooling loads on the 24V side.\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), 1060940 (DPST Relay)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eStep-Down Control Transformer + Relays\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\u003eTEB12K25RTA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eA direct-fit replacement for the Tempstar TEB12K25RTA PTAC. These components are shared across the ICP\/Tempstar\/Heil TEB12K25 packaged terminal unit family — verify your unit's model and serial tag and confirm primary voltage (208\/240V) 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 unit disconnect and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the PTAC front cover and control box panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the transformer and relay wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the primary and secondary leads, unbolt the old transformer\/relays from the control plate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer and relays, reconnect every lead per your photo, and confirm primary taps match line voltage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify 24V at the secondary and proper relay switching on a call for heat\/cool.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo 24V at the secondary — entire control circuit is dead\u003c\/li\u003e\n\u003cli\u003eUnit has line power but thermostat is unresponsive\u003c\/li\u003e\n\u003cli\u003eBlown low-voltage fuse or repeated control-circuit faults\u003c\/li\u003e\n\u003cli\u003eRelays buzzing, chattering, or failing to pull in\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":63021643989363,"sku":"1053004-GEN","price":29.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048411513203,"sku":"1053004","price":38.94,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1053004_23c5de31-d69d-4c1b-b66b-5169775bcba5.jpg?v=1782958563","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-teb12k25rta-208-240v-to-24v-with-relays-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}