Look for soot accumulation around the blower flange

The MAMAC Systems TE-702-B-10-B is a high-precision duct temperature sensor engineered for demanding building automation systems (BAS) and mechanical equipment room applications

and M9220 series power units

this specific part is tailored for 5-inch diameter actuators

Rapid Servicing: The high-clearance design without a splash guard simplifies cleaning and speeds up the "dump and reload" process

Johnson Controls T-4000-3140 Plastic Cover Look for soot accumulation aroundProfessional grade Johnson Controls T 4000 3140 plastic covers are engineered for high performance pneumatic room thermostat applications. This horizontal mount faceplate is compatible with nearly all T 4000 series instruments, excluding the T 4100 and T 4600 models. Constructed from durable, white thermoplastic, the T 4000 3140 features a built in Fahrenheit Celsius thermometer to provide clear ambient temperature feedback for facility maintenance