Allied Air 83l91 Limit Control

Product Description

The ALLIED AIR 83l91 is a limit control designed for use in forced-air heating systems. Limit controls monitor temperature within the heat exchanger or plenum and shut down the burner or heat source when temperatures exceed a safe operating threshold. This protects the system from overheating and prevents damage to the heat exchanger. The 83l91 is installed by licensed HVAC technicians during service calls or system repairs requiring replacement of a failed or out-of-calibration limit switch.

This limit control is suited for residential forced-air furnace applications where thermal protection of the heat exchanger is required. It functions as a safety device in the high-limit circuit, interrupting burner operation when a preset temperature is reached and restoring operation once the system cools to a safe level. It is appropriate for use in standard gas furnace installations requiring an OEM-style limit control replacement.

Key Features

• Thermal limit protection prevents heat exchanger overheating
• Interrupts burner circuit on high-temperature fault condition
• OEM-style replacement for straightforward field installation
• Designed for integration into the high-limit safety circuit of forced-air furnaces

Compatibility

Designed as an OEM-style replacement limit control for residential forced-air gas furnace systems.

Installation Notes

Installation should be performed by a licensed HVAC technician. Disconnect all power to the furnace and shut off the gas supply before beginning work. Verify the replacement limit control matches the mounting configuration and temperature rating of the original device before installation. Work should comply with applicable local mechanical codes and the equipment manufacturer's service documentation.

Technical Specifications

• Manufacturer: Allied Air Enterprises
• Manufacturer Part Number: R40154B016

Standard Information

• Brand: ALLIED AIR
• Manufacturer Part Number: 83l91