Johnson Controls T-4000-3139 Plastic Cover

The Johnson Controls T-4000-3139 is a professional-grade horizontal pneumatic thermostat cover designed specifically for the T-4000 Series room thermostats. Engineered for demanding commercial environments, this white plastic cover provides a clean, uniform look for horizontal-mounted controllers where a blank faceplate cover is required. As a genuine Johnson Controls replacement part, it ensures a precise fit for single or dual-element sensing units without the need for visual monitor windows or external thermometers. This T-4000 series plastic cover features a high-impact, shock-resistant construction to protect sensitive bimetal elements from mechanical damage and environmental debris. Integrating this white horizontal thermostat cover into your HVAC control system ensures your pneumatic control accessories maintain structural integrity and professional aesthetics. With the iconic Johnson Controls logo, it serves as a direct-fit solution for contractors maintaining building automation systems (BAS) that prioritize a tamper-resistant, concealed setpoint design for institutional or commercial facilities.

Key Benefits

• Universal T-4000 Series Compatibility: Fits all standard horizontal T-4000 series pneumatic thermostats, including T-4002 and T-4100 models.
• Industrial Durability: Constructed from vibration-resistant white plastic to withstand high-traffic commercial hallways and mechanical rooms.
• Tamper-Resistant Design: The no-window faceplate prevents unauthorized setpoint adjustments and protects internal bimetal sensors.
• Clean Professional Aesthetic: Features a sleek white finish with the official logo, perfect for modernizing legacy pneumatic systems.
• Simplified Installation: Designed for rapid field replacement on existing horizontal mounting brackets using standard #4-40 hex screws.

Common Questions

Does this cover include a cutout for the thermometer or setpoint adjustment?
No, the T-4000-3139 is a blank "no-window" model designed for concealed applications where temperature readings and setpoint adjustments are managed by authorized technicians only.

Will this work for a vertical mounted thermostat?
This specific part is engineered for horizontal mounting. For vertical configurations, a different T-4000 series cover part number must be specified to ensure the logo and orientation align correctly with the internal thermostat pipehead.

Is the mounting hardware included with the replacement cover?
This item typically includes the plastic cover assembly only. It is recommended to retain your existing #4-40 mounting screws or order the T-4002-617 screw kit if replacements are needed.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.