Protect your HVAC system with industry-proven duct high limit controls manufactured in the USA. Firestat duct limit switches are engineered to detect dangerous temperature increases within ductwork and automatically shut down heating, ventilation, or air conditioning equipment before overheating can cause equipment damage or create a fire hazard.

Whether you’re replacing an existing duct limit switch, specifying controls for a new installation, or purchasing for an apartment complex, commercial building, OEM, or building automation system, Senasys offers reliable solutions built for long-term performance.

Our Products

Adjustable Duct High Limit Controls

Our adjustable models allow the temperature setpoint to be field adjusted from 100°F to 250°F, making them ideal for a wide range of HVAC applications. Available with 5-inch, 7.5-inch, and 11-inch sensing elements, these controls provide installation flexibility while maintaining dependable manual-reset protection.

Ideal for:

• Commercial HVAC systems
• Apartment and multi-family buildings
• Air handlers
• Rooftop units
• Building automation systems (BAS)

Fixed Temperature Duct High Limit Controls

When a predetermined shutdown temperature is required, our fixed temperature models provide dependable operation with factory-set temperatures of 125°F, 165°F, or 200°F. These manual-reset controls deliver consistent protection without the need for field adjustment.

Ideal for:

• OEM equipment
• Code-compliant HVAC installations
• Replacement applications
• Standardized maintenance programs

Every Firestat duct high limit control is 100% tested prior to shipment to ensure consistent operation and long service life.

Need Help Selecting the Right Model?

Not sure which duct limit control you need? Our technical support team can help identify the correct replacement or recommend the best model for your application. We can also cross-reference many popular HVAC duct limit controls and discuss custom solutions for OEM projects.

For larger production quantities, quantity pricing and custom manufacturing options are available. Contact our team to discuss your application and receive a quotation.

Shop duct high limit controls below to find the right product for your needs.