This Lennox 17F21 is typically supplied as the box assembly

Check the spark gap (should be approximately 0

this PTC start relay ensures precise current switching and thermal protection during the critical startup phase

This ensures the thermostatic probe is positioned correctly within the top 6 inches of the tank to accurately sense water temperature

It is ready for install and does not require external software for standard operation

Siemens Building Technology GMA121.1P Actuator 30067439-890 This Lennox 17F21 is typicallyThe Siemens GMA121. 1P is a heavy duty OpenAir electronic damper actuator designed for the rigorous demands of commercial HVAC systems. Engineering for reliability, this 24V spring return actuator delivers 62 lb in torque (7 Nm), making it an ideal choice for managing return air, exhaust, and face and bypass dampers in both constant and variable air volume (VAV) installations. The 2 position control (on off) logic ensures decisive operation, while the