OEM Carrier 40VA Control Transformer HT01BD236 for Model C50A402561

This OEM control transformer (part# HT01BD236) is the factory-specified replacement for the Carrier C50A402561 commercial packaged rooftop unit. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the system goes completely silent: no thermostat response, no staging, no heating or cooling whatsoever. It is often the first component to inspect when a unit shows zero control-circuit activity.

• Specs: 40VA capacity | Primary: 120V AC | Secondary: 24V AC | Replaces OEM part number HT01BD236 | Factory-matched output tolerance for reliable control-circuit operation
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA rating and insulation class, ensuring the secondary voltage holds steady under full load from multiple control components. Generic transformers frequently underperform at rated VA, causing erratic thermostat behavior or nuisance tripping of the internal thermal fuse.
• Install difficulty: 2/5 — Shut off all power at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (to verify 24V output after install). Label or photograph existing wire connections before removing the old transformer. Most technicians complete the swap in under 30 minutes.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse — order before 3 PM local time for guaranteed same-day dispatch.

Compatibility: Engineered specifically for the Carrier C50A402561 commercial rooftop packaged unit. Verify your unit's control-circuit voltage (120V primary / 24V secondary) and VA rating on the data plate before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — no guesswork required.