OEM Carrier 50VA Control Transformer P201-35150 for Model YAC36100YAC104

This genuine OEM step-down transformer is the factory-specified replacement for the Carrier YAC36100YAC104 HVAC system. The transformer reduces incoming line voltage (120/208/240 VAC) down to a safe 24 VAC to power the low-voltage control circuit — including the thermostat, control board, and all 24V relay coils. When it fails, the entire control circuit goes dark: the thermostat loses power, the system stops responding to calls for heating or cooling, and nothing operates. In some cases a shorted secondary will blow the control-circuit fuse repeatedly until the transformer is replaced.

• Specs: 50 VA rating | Primary: 120/208/240 VAC | Secondary: 12/24 VAC | 60 Hz single-phase | CSA listed | OEM Part # P201-35150 (also sold under Totaline brand)
• OEM vs Generic: The OEM P201-35150 is wound to exact VA and voltage tolerances for Carrier control circuits. Generic transformers rated at nominal 50VA frequently run under-tolerance, causing nuisance fuse trips and premature control board failure — especially on systems with high 24V current draw from multiple zone valves or relays.
• Install difficulty: 2/5 — Shut off power at the breaker before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, and spade or ring terminal crimper. Label all wiring connections before removal. Verify secondary output voltage (should read 24–28 VAC) after installation before restoring full system power.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Confirmed factory fit for Carrier model YAC36100YAC104. This transformer is also cross-referenced under the Totaline parts brand (same Carrier Corporation part). Always verify the primary voltage tap and VA rating on your unit's data plate before ordering to ensure correct fitment. Have a question? Our HVAC parts team confirms fitment before you buy — order with confidence and get it shipped today.