OEM Carrier Control Transformer 40VA 120V/24V for Model PH14NA024000AAAA

This OEM control transformer (part number HT01AW229) is the factory-specified replacement for the Carrier PH14NA024000AAAA heat pump system. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, and all low-voltage switching circuits. When this component fails, the entire control circuit goes dark — your thermostat loses power, the system won't respond to any call for heating or cooling, and no relays or contactors will energize. If you're measuring 120V on the primary side but zero volts on the secondary, this transformer is the likely culprit.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Replaces OEM part HT01AW229 | Factory-matched insulation class and VA rating
• OEM vs Generic: This is the factory OEM unit, wound to exact VA and voltage specifications. Generic transformers can run at marginal VA ratings that cause brownouts in the control circuit, leading to random lockouts and nuisance tripping of low-voltage fuses.
• Install Difficulty: 2/5 — Always shut off power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label or photograph all wiring connections before removal. Verify 24V output on the secondary with a multimeter after installation before restoring full power.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PH14NA024000AAAA heat pump systems. Verify your existing transformer's VA rating and primary/secondary voltages against your unit's data plate before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase — no guesswork required.