If it detects a drop in air volume or a blocked flue condition

Industrial Durability: Constructed with heavy-duty materials to resist oxidation and carbon buildup on the flame rod

this 24V gas valve features a slow-opening regulator designed to provide smoother burner ignition and enhanced equipment longevity

As a critical HVAC furnace control board

How do I test the time delay

Johnson Controls A421AET-01 Temperature Control 321894-708 If it detects a dropThe Johnson Controls A421AET 01 is a line voltage electronic temperature control designed for versatile HVACR applications, providing a reliable alternative to traditional electromechanical thermostats. Operating on 120 240 VAC, this SPDT controller features a broad setpoint range of 40 to 212F, making it ideal for both refrigeration and heating logic. Built with a NEMA 1 enclosure for surface mounting, the unit includes a high visibility front panel