check for a closed circuit (continuity) across the terminals at room temperature

this orifice threads directly into the valve body to facilitate rapid field maintenance and prevent hunting or flickering in downstream boilers and furnaces

or visible cracks in the ceramic insulator causing the arc to ground prematurely

OEM Compatibility: Exact fit for the Johnson Controls T-4000 series

Johnson Controls A-4000-635 Filter Element check for a closed circuitThe Johnson Controls A 4000 635 is a high efficiency 5 SCFM filter element designed for critical air filtration within pneumatic control systems. Engineering for reliability, this dry type filter features a 1 2 inch NPT connection and delivers a 99% efficiency rating at 10 microns. Its robust design is purpose built for intake air filtration, effectively removing contaminants to protect sensitive downstream components like the A 4400 Series air