Lennox 49K71 - (49K7101) Therm-O-Disc Limit Control, Contacts Open at 220°F, Manual Reset
The Lennox 49K71 (49K7101) is a precision-engineered high-limit control switch designed for use in residential and light commercial HVAC systems. This Therm-O-Disc limit control acts as a critical safety device that interrupts electrical power when excessive temperatures are detected, helping prevent component damage, fire hazards, and system failures.
Key Features and Benefits:
- Manual Reset Functionality: Unlike automatic reset models, the manual reset design of the 49K71 ensures that the system remains off until a technician investigates and resolves the overheating condition. This promotes system safety and helps prevent repeated cycling during abnormal conditions.
- Temperature Control: The contacts are designed to open at 220°F (104°C), making this component ideal for high-temperature protection in furnaces, fan coils, and air handlers.
- Reliable Therm-O-Disc Construction: Built to withstand harsh operating environments, the limit control is manufactured by Therm-O-Disc—an industry leader in temperature sensing and control technology. The high-quality bimetal disc mechanism ensures reliable temperature response and long service life.
- Compact and Durable Design: The 49K71 is housed in a compact form factor for ease of installation, even in tight HVAC compartments. Its rugged materials resist corrosion, vibration, and thermal stress.
- OEM Replacement for Lennox Systems: Specifically engineered to meet Lennox’s high-performance standards, this control is a direct replacement part for a variety of Lennox furnace and HVAC units. It is commonly used in high-limit control circuits to shut down heat sources when safe operating limits are exceeded.
- Wide Compatibility: Suitable for many gas furnaces, electric air handlers, and rooftop units requiring a 220°F manual reset limit switch. Always confirm with the equipment manual or manufacturer specifications for exact fit.
- Part Number: 49K71
- Manufacturer Number: 49K7101
- Type: Manual Reset Limit Control
- Temperature Rating: Opens at 220°F (104°C)
- Contact Style: SPST (Single Pole, Single Throw)
- Mounting: Surface or bracket-mounted (varies by unit design)
- Applications: Over-temperature protection in HVAC systems
- High limit switch in gas furnaces
- Safety control in electric heating elements
- Temperature cut-off for blower or air handler assemblies