Johnson Controls T-4000-2138 Plastic Cover maintaining system integrity behind the

maintaining system integrity behind the primary safety loop

Common Questions How do I know if my furnace door switch is faulty

ensuring a direct fit without the need for field modifications

ensuring a secure fit on the valve stem to prevent slipping or inaccurate settings

This protects the HVAC transformer from overheating during an overload or short circuit

Johnson Controls T-4000-2138 Plastic Cover maintaining system integrity behind theThe Johnson Controls T 4000 2138 is a professional grade beige plastic thermostat cover designed specifically for T 4000 series pneumatic room thermostats. This field standard component provides a clean, streamlined aesthetic for commercial HVAC systems where tamper resistance and a minimalist profile are required. Engineered for versatility, the T 4000 2138 supports both horizontal and vertical mounting configurations, accommodating various pneumatic