Knox Sales Company 4100 Pb Thermodisc High Limit Control

Product Description

The KNOX SALES COMPANY 4100 PB is a dual-pole thermodisc high limit control designed to protect heating equipment from unsafe operating temperatures. When the monitored surface or air temperature exceeds the setpoint, the device opens the circuit and shuts down the heat source, preventing damage to equipment and reducing risk of hazardous conditions. This type of open-on-rise, manual or automatic-reset high limit is commonly found in furnaces, boilers, unit heaters, and related HVAC or hydronic heating systems. It is installed by licensed HVAC technicians and heating equipment service professionals.

The 4100 PB thermodisc high limit control is suited for residential and light commercial heating applications where temperature-based safety cutoff is required. Thermodisc-style limits are used in gas furnaces, electric furnaces, boilers, and other heating appliances to meet equipment safety requirements. The dual-pole configuration interrupts both legs of the controlled circuit, making it appropriate for applications where full circuit isolation is needed on a high-limit trip event.

Key Features

• Dual-pole design interrupts both circuit legs for full isolation on high-limit trip
• Open-on-rise operation shuts down heat source when temperature exceeds setpoint
• Thermodisc sensing element provides reliable temperature response
• Suitable for furnace, boiler, and unit heater high-limit protection applications

Compatibility

Designed as an OEM-style replacement thermodisc high limit control for residential and light commercial heating equipment requiring dual-pole high-limit safety protection.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified heating equipment service professional. Always disconnect power to the unit and shut off the fuel supply before servicing any high-limit control. Mount the thermodisc firmly against the designated sensing surface and verify all wiring connections are secure before restoring power. Follow applicable local codes and equipment manufacturer guidelines during installation.

Technical Specifications

• Control Type: Dual-Pole Thermodisc High Limit
• Operation: Open on Rise

Standard Information

• Brand: KNOX SALES COMPANY
• Manufacturer Part Number: 4100 PB