This Lennox 42W92 (LB-74928) transformer is a dependable 40 VA replacement component designed for a wide range of Lennox heating and cooling systems. Built for consistent low-voltage power delivery, it features a 208/240 VAC primary input and a 24 VAC secondary output, supporting safe and stable control circuit performance in residential and light commercial HVAC units. Its robust construction and OEM-level compatibility make it a trusted choice for technicians performing maintenance, system upgrades, or emergency repairs.

This transformer is engineered to maintain system reliability, prevent voltage irregularities, and ensure proper operation of thermostats, control boards, relays, and other 24-volt accessories. Whether replacing a failed transformer or performing preventative service, the 42W92 offers long-term durability and precise electrical output.

 

Key Features:

• OEM Lennox LB-74928 transformer for reliable HVAC system performance
• 40 VA capacity designed for stable low-voltage power distribution
• Primary voltage: 208/240 VAC, 60 Hz
• Secondary voltage: 24 VAC output for control circuits
• Supports thermostats, boards, relays, gas valves, and safety controls
• High-quality construction suitable for residential and commercial equipment
• Direct-fit replacement for select Lennox systems