Proper adjustment of this primary air shutter control is essential for achieving a stable flame

while red indicates an active alarm state with a maximum 40-second response time

this 4520-2031-000 switch may fit other units if the temperature range and mounting specifications align

The Emerson Alco 065406

Technicians should look for hairline cracks at the hub

Schneider Electric (Barber Colman) TC-5231 Thermostat 30067439-890 Proper adjustment of this primaryThe Schneider Electric TC 5231 is a commercial grade low temperature thermostat designed for high performance freeze protection in AHU coils and heat exchangers. This single pole double throw (SPDT) controller features an adjustable 35F to 60F setpoint range and a 20 foot vapor charged sensing capillary, making it ideal for monitoring temperatures across large coil faces. As the direct replacement for the legacy Barber Colman 2284 421, it integrates