gas furnace will not come back on
The most common reason is the flame sensor rod is dirty. If this is the problem, then remove the flame sensor rod and gently clean it with steel wool or a dollar bill. Flame sensor rods need to conduct electricity, but if the rod gets coated with dirt then it insulates the flame sensor rod and electricity cannot conduct anymore. Flame sensor rods tend to get dirty more quickly when the furnace is located in the laundry room because the air in the laundry room tends to have more dust.