{"product_id":"icp-40va-120v-to-24v-transformer-for-sup20m2401bia-oem-l01f009-ships-today","title":"ICP 40VA 120V to 24V Transformer for SUP20M2401BIA — OEM L01F009 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM kit covers the L01F009 control transformer (TRANS 120\u0026gt;24 40VA) and the L01H009 24VAC relay (AG90-23242-024W) for the ICP \/ Tempstar \/ Heil SUP20M2401BIA. The transformer steps 120-volt line power down to 24 volts at 40VA to power the thermostat, control board, and relay circuit, while the relay switches a line-voltage load on command from that 24V circuit. A failed transformer leaves the entire low-voltage system dead — no thermostat response and a blank control board — while a failed relay causes mis-sequencing or stuck loads. Replacing with exact OEM parts restores correct control voltage and switching.\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\u003c\/td\u003e\n\u003ctd\u003eL01F009\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelay Part\u003c\/td\u003e\n\u003ctd\u003eL01H009 (AG90-23242-024W)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eStep-down Transformer + Relay\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Voltage\u003c\/td\u003e\n\u003ctd\u003e120 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Voltage\u003c\/td\u003e\n\u003ctd\u003e24 VAC\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Tempstar \/ Heil\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eSUP20M2401BIA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDesigned for the ICP-family SUP20M2401BIA and shared across many ICP, Tempstar, Heil, and Comfortmaker units running a 120V primary \/ 24V 40VA control circuit. Confirm your primary voltage is 120V 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 service \/ control panel to reach the transformer and relay.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary, secondary, and relay wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect leads, then unfasten the failed transformer and relay.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new L01F009 and L01H009 and reconnect each wire per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24VAC at the secondary and proper relay pull-in.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo 24V control power; blank board and unresponsive thermostat.\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown low-voltage fuse.\u003c\/li\u003e\n\u003cli\u003eOverheated, buzzing, or burnt-smelling transformer.\u003c\/li\u003e\n\u003cli\u003eRelay chatter or a load that stays on or won't start.\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":63021831913843,"sku":"L01H009","price":44.2,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047369064819,"sku":"L01H009-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-L01H009_cd2e8bec-cd9e-4c1a-8190-0fee430b72cb.jpg?v=1782882296","url":"https:\/\/nationalhvacparts.com\/products\/icp-40va-120v-to-24v-transformer-for-sup20m2401bia-oem-l01f009-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}