Founded in 1900, Coleman Heating and Air Conditioning has been manufacturing HVAC equipment for residential customers for over 100 years. Coleman furnaces contain two internal safety components—known as high-limit switches—that are designed to stop electricity from reaching the gas ignition valve if the furnace overheats to dangerous temperatures. The furnace's lower limit switch is programmed for automatic reset, but the upper limit switch must be manually reset. Performing a manual reset on a Coleman upper limit switch is a quick and simple process.
Open the cover of your circuit breaker box. Identify the circuit breaker switch that controls the electricity to your Coleman furnace. Move the switch into the "Off" position.
Examine the furnace to locate the upper limit switch. Look for a small round component with a raised red button at its center.
Depress and release the red "Reset" button in the middle of the upper limit switch.
Return to the circuit breaker box. Move the furnace's circuit breaker switch into the "On" position.