{"product_id":"icp-24v-transformer-for-wamc18004a1-40va-control-transformer-ships-today","title":"ICP 24V Transformer for WAMC18004A1 — 40VA Control Transformer | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis is a genuine OEM 24-volt control transformer (part number 202300900212) for the ICP Tempstar Heil WAMC18004A1 air handler. The transformer steps down incoming line voltage to the 24V control voltage that powers your thermostat, contactor coil, relays, and safety controls. A 40VA rating provides the secondary current needed to energize these low-voltage components reliably. When the control transformer fails, the entire low-voltage circuit goes dead: the thermostat goes blank, the contactor will not pull in, and the system stops responding to a call for cooling or heating. Common causes include a shorted thermostat wire, a seized contactor coil overloading the secondary winding, voltage spikes, and age-related insulation breakdown.\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 Number\u003c\/td\u003e\n\u003ctd\u003e202300900212\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eControl \/ Step-Down 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\u003e40 VA\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\u003eEngineered as the direct OEM replacement for the ICP Tempstar Heil WAMC18004A1. ICP also builds equipment under the Comfortmaker, Arcoaire, and KeepRite labels, so this transformer fits matching control assemblies across those families. Confirm the printed part number on your existing transformer before ordering.\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 at the breaker and disconnect switch, then verify zero voltage with a multimeter on both line and load terminals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the unit service panel to expose the control box and transformer mounting bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire and terminal connection before disconnecting anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the primary (line) and secondary (24V) leads, then unscrew the transformer from its bracket or control panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect the primary and secondary leads exactly per your photo, and confirm all spade connections are tight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify 24V across the secondary terminals and that the thermostat and contactor respond.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBlank thermostat display with confirmed line voltage at the unit\u003c\/li\u003e\n\u003cli\u003eContactor will not energize on a call for cooling\u003c\/li\u003e\n\u003cli\u003eNo measurable 24V at the secondary terminals\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visible scorching on the transformer body\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":"ICP","offers":[{"title":"Direct Replacement","offer_id":63021614367091,"sku":"202300900212-GEN","price":32.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63047946207603,"sku":"202300900212","price":41.6,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-202300900212_9e06fdbe-f9eb-431a-b42a-c7f554da3bdc.jpg?v=1782881939","url":"https:\/\/nationalhvacparts.com\/products\/icp-24v-transformer-for-wamc18004a1-40va-control-transformer-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}