How a Dirty Flame Sensor Prevents Your Gas Furnace from Staying Lit

When you turn on your heater and it shuts down three seconds later, it isn’t necessarily broken. A micro-layer of carbon on the flame sensor triggers this built-in safety mechanism.

When you turn on your heater and it shuts down three seconds later, it isn’t necessarily broken. A micro-layer of carbon on the flame sensor triggers this built-in safety mechanism.