Understanding Common Furnace Safety Features

Today’s furnaces come equipped with a set of built-in furnace safety features. These are designed to protect your family from danger in the event of a furnace malfunction. Understanding and working with these features can increase the margin of safety that you and your family count on to make your Charlotte, NC home a haven of comfort and worry-free living.

Thermocouple or Mercury Flame Sensor

The thermocouple is a safety feature in older furnaces with continuously burning pilot lights. This critical device is designed to turn off the gas supply to the furnace when it detects that the pilot light is off. This prevents unburned gas from building up inside the furnace and leaking out into your home, creating a highly dangerous situation.

Modern furnaces use electronic ignition to light the pilot immediately before each heating cycle. In these systems, a mercury flame sensor does the same job. It senses when the flow of gas must be interrupted for proper furnace functioning and safety.

Flame Roll-Out Switch

Another vital safety feature of quality heating products is the flame roll-out switch, a type of limit switch that prevents flames from spreading beyond the combustion chamber, a condition known as “roll-out.” Roll-out can be dangerous. You can help keep your family safe by keeping all flammable materials as far away from your furnace as possible. You’ll need to have a tripped roll-out switch reset by an HVAC professional.

Plenum Thermostat Limit Switch

Also known as a fan limit switch, this furnace safety device senses the temperature of the air above the heat exchanger, turning the fan on when the air is warm enough to begin delivering heat to your home. This switch also prevents damage to the heat exchanger, preventing it from heating to a dangerously high temperature. If the fan fails to activate, the switch will turn off the gas.

To keep your furnace safety features operating effectively, be sure to schedule regular furnace tune-ups with Lakeside Heating & Air Conditioning. Call our heating experts at (704) 285-1070 to make sure your furnace continues operating safely.