OEM Carrier 40VA Control Transformer 120V–24V for Model PG8DAA048095ACJA

This OEM control transformer (part number HT01BC116, superseded by HT680054) is the factory-specified replacement for the Carrier PG8DAA048095ACJA gas furnace. The transformer steps down 120V line voltage to 24V AC, powering the entire low-voltage control circuit — including the thermostat, gas valve, inducer relay, and control board. When it fails, the furnace goes completely dark: no thermostat response, no ignition attempt, nothing. A failed transformer is one of the most commonly misdiagnosed no-heat calls, so always verify 24V output at the R and C terminals before condemning other components.

• Specs: 120V primary | 24V secondary | 40VA rating | 50/60 Hz | Single-phase | Foot-mount configuration | Wire lead connections
• OEM vs Generic: This OEM unit meets exact Carrier factory tolerances for VA output and insulation class. Generic transformers often run under-rated VA, causing voltage sag that triggers nuisance lockouts on sensitive control boards and gas valves.
• Install difficulty: 2/5 — Shut off power at the breaker and verify zero voltage before disconnecting leads. Tools needed: flathead and Phillips screwdriver, multimeter, needle-nose pliers. Photograph all wiring before removal. Always check for a blown 3A inline fuse on the secondary — a shorted low-voltage circuit will immediately blow a new transformer if the fault is not cleared first.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse on all in-stock orders.

Compatibility: Directly fits Carrier model PG8DAA048095ACJA gas furnaces. OEM part HT01BC116 has been superseded by HT680054 — both part numbers are fulfilled with the current production unit. Also cross-references: HT01BC115, HT01BC120, HT01BB126, HT01AW115, 322666-701, and B1810113. Verify primary voltage on your unit's data plate before ordering. Questions about fitment? Our HVAC parts specialists confirm compatibility before you buy.