OEM Carrier Control Transformer 120V-24V 40VA (HT01BC116) for Model PG9MAB036080LBSA

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG9MAB036080LBSA gas furnace. It converts 120V AC line voltage down to 24V AC to power the low-voltage control circuit — including the thermostat, control board, gas valve, and all safety switches. When the transformer fails, the entire control circuit goes dead: the thermostat goes blank, the furnace won't respond to any call for heat, and the control board shows no signs of life. A shorted low-voltage component (such as a faulty zone valve or wiring fault) is the most common cause of transformer failure, so always inspect the secondary circuit before installing a replacement.

• Specs: Primary 120V AC | Secondary 24V AC | 40VA rated | Foot-mount configuration | Wire lead connections | 60 Hz
• OEM vs Generic: This OEM unit is built to Carrier's exact VA rating and voltage tolerance specs. Generic transformers often use undersized cores that run hot under normal furnace loads, accelerating insulation breakdown and shortening service life — as one verified buyer noted, generic units may not even mount correctly without modification.
• Install difficulty: 2/5 — Shut off power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Photograph all existing wiring before disconnecting. Check secondary voltage (R-to-C terminals on the control board) after install to confirm 24–28V AC output.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier PG9MAB036080LBSA gas furnaces. Note: OEM part number HT01BC116 has been superseded by Carrier part HT680054 — this listing ships the current factory-authorized replacement. Also cross-references HT01BC115, HT01BC116B, HT01BB126, HT01BC120, and HT01AW115. Verify primary voltage on your unit's data plate before ordering. Our team is available to confirm fitment — just reach out before you buy.