OEM Carrier Furnace Control Transformer 120V–24V 40VA for Model PG9MAA036040AAKA

This OEM step-down control transformer is the factory-specified replacement for the Carrier PG9MAA036040AAKA gas furnace, sold under OEM part number HT01BC116 (superseded by HT680054). The transformer converts 120V line power down to 24V AC to energize the low-voltage control circuit — powering the thermostat, gas valve, inducer relay, and IFC control board. When this transformer fails, the entire control circuit goes dead: the thermostat displays nothing, the furnace refuses to respond to a heat call, and no ignition sequence is ever initiated. It is one of the first components to check during a no-power diagnostic.

• Specs: Primary Voltage: 120V AC | Secondary Voltage: 24V AC | VA Rating: 40VA | Frequency: 60 Hz | Phase: Single | Mounting: Foot mount | Connection: Wire leads with insulated female quick-connects
• OEM vs Generic: This OEM unit is wound to exact Carrier factory tolerances, ensuring stable 24V output under full load. Generic transformers frequently undervolt the control circuit under load, causing nuisance lockouts, erratic board behavior, and premature component wear.
• Install difficulty: 2/5 — Turn off power at the breaker and verify 0V before touching any wiring. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wire connections before removal. Check the low-voltage circuit for short conditions before energizing the new transformer.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered by 3 PM local time.

Compatibility: Designed for the Carrier PG9MAA036040AAKA gas furnace. OEM part number HT01BC116 has been superseded by HT680054 — both are covered by this listing. Also replaces HT01BC115, HT01BB126, HT01CT120, HT01BC120, HT01AW115, and several additional cross-reference numbers. Always confirm your unit's data plate voltage before ordering. Need fitment verification? Our HVAC parts team confirms compatibility before you buy — order now and get it shipped today.