{"product_id":"icp-40va-transformer-for-sh12516b-120v-to-24v-class-2-ships-today","title":"ICP 40VA Transformer for SH12516B — 120V to 24V Class 2 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM 40VA control transformer (part number 1540352) steps incoming 120-volt line power down to the 24-volt Class 2 control voltage that your ICP SH12516B furnace's thermostat, gas valve, and control circuits require. The low-voltage 24V control system depends entirely on this transformer; when it fails, nothing in the low-voltage circuit can energize. A 40VA rating provides ample capacity for standard residential control loads. Common failure symptoms include a completely dead thermostat, a system that will not start, a blown low-voltage fuse, a burning smell from the control compartment, or a transformer that hums loudly and runs hot to the touch.\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\u003e1540352\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Heil \/ Tempstar \/ Comfortmaker\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\u003e120V\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\u003eClass\u003c\/td\u003e\n\u003ctd\u003eClass 2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDirect OEM replacement for the ICP \/ Tempstar \/ Heil SH12516B and other ICP-family equipment using the 1540352 transformer. Always confirm the existing transformer is rated 120V primary to 24V secondary at 40VA 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 disconnect and breaker, then verify zero voltage at the transformer terminals with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace service panel to expose the control compartment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph all primary and secondary wire connections before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the 120V primary leads and 24V secondary leads, then unbolt the old transformer from the bracket.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, reconnect primary to line voltage and secondary to the 24V control circuit per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify 24V across the secondary terminals, then confirm the thermostat and gas valve energize on a call for heat.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDead thermostat or display with line power confirmed present\u003c\/li\u003e\n\u003cli\u003eRepeatedly blown 3A low-voltage control fuse\u003c\/li\u003e\n\u003cli\u003eNo 24V reading across the secondary terminals\u003c\/li\u003e\n\u003cli\u003eLoud humming, overheating, or a burnt-insulation smell\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":"OEM","offer_id":63021834076531,"sku":"1540352","price":28.6,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047375126899,"sku":"1540352-GEN","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1540352_ffc6cc24-9915-4ca6-9ef3-b03732d53efb.jpg?v=1782882464","url":"https:\/\/nationalhvacparts.com\/products\/icp-40va-transformer-for-sh12516b-120v-to-24v-class-2-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}