A furnace that starts then stops is a common issue also known as short cycling. The furnace starts to heat the home, but turns off again quickly after only a short amount of time has passed. It is not normal for a heating cycle to be so fast, and short cycling can cause damage to the furnace. Furnace repair may be needed to correct the underlying issue causing short cycling.
A furnace that is the right size for the home should run three to eight heating cycles in an hour period (this will vary based on the characteristics of the home and preferences of occupants). When the furnace cycles more often than this, short cycling is possible – it may also be possible that extreme temperatures are causing the need for more frequent cycles, or your furnace is undersized or requires additional insulation.
Common causes of furnace short cycling include:
Flame rod failure. When the furnace’s flame rod fails to sense the burner flame, the furnace will shut down. Cleaning the flame rod may resolve this issue.