{"product_id":"carrier-fk4cnb006000ahaa-transformer-h3hww2","title":"OEM Carrier Transformer 40VA 120V\/24V for FK4CNB006000AHAA","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer HT01CN236 for Model FK4CNB006000AHAA\u003c\/h1\u003e\u003cp\u003eThis OEM control transformer (part# \u003cstrong\u003eHT01CN236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier FK4CNB006000AHAA\u003c\/strong\u003e fan coil air handler. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, and any connected zone controls. When this component fails, the result is total control loss: your thermostat goes dark, the system ignores calls for heating or cooling, and nothing responds. It is often misdiagnosed as a thermostat or control board failure before the transformer is checked.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V AC | Secondary: 24V AC | Class 2 transformer | Direct OEM replacement for part# HT01CN236\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This factory OEM transformer is wound to exact VA and voltage tolerances for the FK4CNB006000AHAA control board. Generic transformers often under-deliver on VA capacity, causing nuisance trips on the built-in thermal overload — especially when zone boards or accessories are connected.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (verify 0V before touching terminals). Label or photograph existing wire connections before disconnecting the primary and secondary leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the \u003cstrong\u003eCarrier FK4CNB006000AHAA\u003c\/strong\u003e fan coil air handler. Always verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate before ordering. If you are unsure of fitment, our HVAC parts specialists verify compatibility before you order — no guesswork required.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909500359027,"sku":"CARRIE-FK4CNB006000AHAA-TRANSFORMER-HT01CN236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909500391795,"sku":"CARRIE-FK4CNB006000AHAA-TRANSFORMER-HT01CN236-GEN","price":18.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01CN236_a5726369-bf7c-49cc-9b1f-13f5809d3313.jpg?v=1782941081","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fk4cnb006000ahaa-transformer-h3hww2","provider":"National HVAC Parts","version":"1.0","type":"link"}