OEM Carrier 40VA Control Transformer for Model FA4ANC036005AGAA

This OEM Carrier control transformer (part# HT01CN236) is the factory-specified replacement for the FA4ANC036005AGAA air handler unit. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage control circuits. When it fails — often due to a shorted control wire, failed board, or simple age — nothing in the system responds: the thermostat goes dark, the air handler won't energize, and no heating or cooling call is answered. If you've confirmed 120V at the air handler but zero voltage at the 24V secondary terminals, this transformer is your fix.

• Specs: 40VA rating | 120V primary / 24V secondary | Direct OEM replacement | Part# HT01CN236 | Factory-matched output for stable control circuit operation
• OEM vs Generic: OEM transformers from Carrier maintain precise VA output and insulation ratings to protect downstream boards and thermostats. Generic units often underrate VA load capacity, leading to overheating and premature failure — especially when multiple zones or accessories are connected.
• Install Difficulty: 2/5 — Shut off the disconnect and verify power is off before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label or photograph all wiring before disconnecting. Test 24V output at secondary terminals after installation to confirm proper operation.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered before cutoff.

Compatibility: Designed for the Carrier FA4ANC036005AGAA air handler (3-ton, single-stage R-410A). Always verify your existing transformer's VA rating and primary/secondary voltage on the data plate or wiring diagram inside the unit panel before ordering. Our parts team is available to confirm fitment — reach out before you order if you have any questions.