The Lennox 104824-01 OEM HVAC Control Transformer is a 40 VA electrical transformer designed for compatible Lennox heating and cooling equipment requiring a 24-volt control power supply.

Also identified by Lennox Catalog Number 38M45, this transformer converts incoming 208/240 VAC primary voltage into 24 VAC secondary voltage, providing low-voltage power for compatible HVAC control circuits.

The Lennox 104824-01 Transformer is commonly associated with HVAC electrical control applications where a 24 VAC supply is required for thermostats, relays, contactors, control boards, and other low-voltage components.

Featuring a 40 VA capacity and 60 Hz frequency rating, this OEM replacement transformer is designed to support the electrical requirements of approved Lennox equipment.

Ideal for professional HVAC maintenance and electrical repairs, the Lennox 104824-01 provides a factory replacement solution for compatible heating and air-conditioning systems.

Key Features & Function

• Brand: Lennox
• Manufacturer Part Number: 104824-01
• Lennox Catalog Number: 38M45
• Genuine Lennox OEM replacement transformer
• Power Rating: 40 VA
• Primary Voltage: 208/240 VAC
• Secondary Voltage: 24 VAC
• Frequency: 60 Hz
• Steps down line voltage for HVAC control circuits
• Supplies low-voltage power to compatible electrical components
• Designed for approved Lennox HVAC applications
• Suitable for professional HVAC maintenance and repair

Product Details & Specifications

Specification Note: The voltage ratings, frequency, and 40 VA capacity are based on the supplied product description. Physical dimensions, mounting configuration, lead colors, and terminal arrangements should be confirmed before installation.

HVAC Depot Pro Tip

A failed HVAC transformer can prevent the thermostat, control board, or other 24-volt electrical components from receiving the power needed to operate.

Before replacing the Lennox 104824-01, determine whether the transformer has failed or whether an electrical short or excessive load caused the original component to stop working.

Recommended diagnostic checks:

1. Verify the equipment model and serial number.
2. Confirm the original transformer part number is 104824-01.
3. Measure the incoming primary voltage.
4. Verify the correct 208V or 240V primary connection.
5. Check the 24 VAC secondary output.
6. Inspect low-voltage wiring for shorts or damaged insulation.
7. Check contactor coils, relays, and other connected loads.
8. Verify the total control circuit load does not exceed 40 VA.
9. Inspect transformer wiring and mounting connections.

HVAC Depot Pro Tip: A 40 VA transformer rated at 24 VAC can supply approximately 1.67 amps of nominal secondary current. Exceeding the transformer's capacity can cause overheating, voltage drop, or premature failure.

Important: Always match the primary voltage connections to the actual equipment supply voltage. Incorrect wiring can damage the transformer or connected HVAC controls.

Disconnect electrical power before servicing. Installation should be performed by a qualified HVAC technician.

Equipment / Model Compatibility

The Lennox 104824-01 / 38M45 is intended for select Lennox heating and cooling equipment requiring a 40 VA, 208/240 VAC primary, 24 VAC secondary control transformer.

Exact compatible equipment models have not been independently verified.

Before ordering, confirm:

• Complete Lennox equipment model number
• Equipment serial number
• Original transformer part number
• Required primary voltage
• Required 24 VAC secondary output
• Minimum 40 VA capacity
• Frequency rating
• Mounting dimensions
• Electrical terminal or wire-lead configuration

Compatibility Notice: Matching voltage and VA ratings alone does not guarantee physical or electrical compatibility. Confirm manufacturer-approved replacement information before purchasing.