a cloud of unignited gas can accumulate. The sensor allows the pilot light to be automatically re-ignited if the flame is no longer present. The circuit is a surprisingly simple one, with a PNP ...

If the sensor cannot detect a flame, it will shut down the furnace to prevent unburned gas from escaping. Residue buildup can ...

Blower fan: A small electric fan and motor that directs warm air from the furnace to various parts of the home according to heat demands. Flame detector: Designed to prevent gas from building up ...