{"product_id":"icp-24v-transformer-for-zamb001aha3-spst-40va-control-ships-today-1","title":"ICP 24V Transformer for ZAMB001AHA3 — SPST 40VA Control | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM 24V control transformer (ICP part #1057251) supplies the low-voltage power that operates the thermostat, relays, and control circuits in your air handler or furnace. Rated at 40VA, it steps line voltage down to 24V to drive the SPST control loop. When a control transformer fails, the entire 24V circuit goes dead: the thermostat screen blanks, contactors and relays will not energize, and the system will not start. Common failure causes include a shorted secondary winding, an overloaded control circuit, or repeated voltage spikes that overheat and open the windings.\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\u003e1057251\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eControl Transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP (Tempstar \/ Heil)\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\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSwitch Action\u003c\/td\u003e\n\u003ctd\u003eSPST\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect-fit replacement for ICP, Tempstar, Heil, and Comfortmaker equipment that uses the 1057251 control transformer, including model ZAMB001AHA3. Confirm the primary voltage and VA rating against your existing transformer before installing.\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 control-box\/service panel to reach the transformer.\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 — Disconnect the leads, unbolt the transformer from its mounting bracket, and remove it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect primary and secondary leads per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary and normal control operation.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eBlank thermostat or no 24V at the control board\u003c\/li\u003e\n\u003cli\u003eContactors and relays will not pull in\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown low-voltage fuse\u003c\/li\u003e\n\u003cli\u003eTransformer is hot, buzzing, or visibly scorched\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":"ICP","offers":[{"title":"OEM","offer_id":63027185811827,"sku":"1057251","price":44.2,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047360905587,"sku":"1057251-GEN","price":34.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1057251_7dba2def-bbb8-4791-9820-676492947222.jpg?v=1782882049","url":"https:\/\/nationalhvacparts.com\/products\/icp-24v-transformer-for-zamb001aha3-spst-40va-control-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}