Lennox 21W89 Transformer/Relay Refrigerant position the bulb at either

position the bulb at either the 10 o’clock or 2 o’clock position on a horizontal run and wrap it completely with the provided insulation to prevent ambient temperature interference

As a gas pressure safety switch

the contacts must be closed during normal operation to allow ventilation

Ensure your heating system is ready for propane operation with the Armstrong Furnace ALPKT389-2 Conversion Kit

Lennox 21W89 Transformer/Relay Refrigerant position the bulb at eitherFor veteran technicians looking to maintain system integrity, the Lennox 21W89 Transformer Relay is a critical OEM component engineered for precision HVAC voltage regulation. This heavy duty transformer relay assembly is designed to step down 120V line voltage to a consistent 24VAC output at 40VA, 50 60Hz, ensuring stable low voltage control circuit operation even in demanding environments. By integrating a high performance electromechanical relay,