3
Upflow furnace components
Relief Box
Rating Plate
Gas Valve Control Knob (On/Off)
Gas Valve
Gas Burner
Flame Sensor
Air Filter Retainer
Air Filter
Blower and Blower Motor
Draft Safeguard Tube and Switch
Gas Manifold
Manual Reset Limit Switch
Hot Surface Ignitor
Blower Door Safety Switch
4
1
2
3
4
5
6
7
8
9
3
Downflow/horizontal furnace components
Manual-Reset Auxiliary Limit Switch
Blower and Blower Motor
Relief Box
Gas Valve Control Knob (On/Off)
Gas Valve
Gas Burner
Rating Plate
Blower Door Safety Switch
Draft Safeguard Tube and Switch
Gas Manifold
Manual Reset Limit Switch (2)
Hot Surface Ignitor
Flame Sensor
1
2
3
4
5
6
7
8
9