OEM Carrier Furnace Transformer 120V–24V 40VA for Model PG9MAA036080AFKA

This OEM step-down transformer is the factory-specified control circuit replacement for the Carrier PG9MAA036080AFKA gas furnace. Its job is to convert 120V line voltage down to a steady 24V AC supply that powers every low-voltage component in the system — the thermostat, gas valve, control board, inducer relay, and ignition circuitry. When the transformer fails, the result is complete loss of control power: the thermostat goes blank, nothing responds, and the furnace will not attempt to start. A failed transformer is often the culprit when a system appears completely "dead" even though the breaker is on and line voltage is present at the unit.

• Specs: 120V primary input | 24V AC secondary output | 40VA rating | 60 Hz | Foot-mount design | Wire lead connections | Replaces OEM part HT01BC116 (current OEM successor: HT680054)
• OEM vs Generic: This OEM transformer is wound to exact factory VA and voltage tolerances. Generic transformers often run outside spec, causing nuisance tripping of the internal thermal overload or insufficient current capacity to drive multiple 24V loads simultaneously — a common problem in multi-stage systems like the PG9MAA036080AFKA.
• Install difficulty: 2/5 — Turn off power and confirm 0V at the transformer primary before touching any wiring. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all wire connections before disconnecting. Verify 24V output with a multimeter across the secondary leads after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3PM local time.

Compatibility: Designed for the Carrier PG9MAA036080AFKA gas furnace and confirmed to fit across a wide range of Carrier, Bryant, and Payne furnace platforms sharing the same 120V–24V 40VA transformer specification. Always verify your existing transformer's input voltage, output voltage, and VA rating on the data plate before ordering. Our fitment team is available to confirm compatibility before you buy — just reach out with your model number.