A limit control is a heat-actuated switch positioned above or beside ______.

A limit control is a heat-actuated switch positioned above or beside ______.

• A. heat exchangers
• B. condensate line
• C. air intake
• D. thermostat

Answer: (A)

Limit controls are safety devices that automatically shut off the burner when the furnace overheats. They are heat-actuated switches placed above or beside the heat exchanger so they can sense rising furnace temperatures right at the source of heat and trip quickly if overheating occurs. If they were mounted on the condensate line, air intake, or thermostat, they wouldn’t reliably monitor the critical temperature near the heat-producing components—condensate lines aren’t a heat source, the air intake reflects outside air, and the thermostat measures room temperature, not the furnace’s internal temperature. Placing the limit control near the heat exchanger provides timely protection against dangerous overheating.

Limit controls are safety devices that automatically shut off the burner when the furnace overheats. They are heat-actuated switches placed above or beside the heat exchanger so they can sense rising furnace temperatures right at the source of heat and trip quickly if overheating occurs. If they were mounted on the condensate line, air intake, or thermostat, they wouldn’t reliably monitor the critical temperature near the heat-producing components—condensate lines aren’t a heat source, the air intake reflects outside air, and the thermostat measures room temperature, not the furnace’s internal temperature. Placing the limit control near the heat exchanger provides timely protection against dangerous overheating.