16
Gas Control Layout
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11
12
1.
Amplifier -
Converts the signal from the discharge air stat to a working voltage to control the
modulating gas valve. (Electronic Modulation Only)
2.
Ignition Control -
Controls pilot and burner ignition and flame safe guard operation.
3.
24V Transformer -
Transforms 120V control voltage to 24V control voltage for gas controls.
4.
Serial Plate -
This contains important information about the furnace. If looking for replacement parts from
the manufacturer, this has part numbers you will need to order the correct parts.
5.
Combination Gas Control Valve -
This valve contains main pressure regulator, safety shut off valves, pilot
regulator, and manual shut off knob. For staged control this valve also controls 50% and/or 100% fire.
6.
Modulating Valve -
Modulates gas to main burner for proper furnace discharge temperature. (Electronic
Modulation Only)
7.
Power Junction Box -
120V Power is connected here from control center by factory.
8.
Gas Designation Disk -
Slide to the side to view proper pilot establishment.
9.
Burner Slide Out Tray -
Burner slides out for ease of service.
10. Manifold Pressure Test Port -
For testing of proper gas pressures.
11. Pilot Gas Line
12. High Temperature Limit Switch -
Protects furnace from overheating. Auto reset device.
When servicing, repairing or replacing parts on these units, always give the complete model number,
serial number, and replacement part numbers from the units serial plate.
