A yellow flame often indicates a partial blockage or incorrect gas orifice size

it will likely trigger a lockout

where it can accurately monitor the internal air temperature passing over the heat exchanger

Can this relay replace a 90-66 model

Schneider Electric (Barber Colman) 2212-118 Thermostat 30067439-890 A yellow flame often indicatesAs a veteran HVACR technician, I know that when you're looking for a reliable pneumatic room thermostat, consistency and ease of field calibration are paramount. The Schneider Electric 2212 118 (formerly Barber Colman) is a heavy duty direct acting thermostat engineered for precise proportional control of pneumatic actuators and damper control systems. This two pipe thermostat features a highly sensitive bimetal sensing element and a pilot operated