| Hi Fire |
| |
| (2nd Stage) | ||
| Manifold Pressure | ||
|
| Low Fire | |
|
| (1st Stage) | |
|
| Manifold Pressure | |
Manual |
| Adjustment | |
|
| ||
Gas |
| Electrical | |
Switch |
| Connection | |
|
| Manifold | |
|
| Pressure | |
|
| Tap | |
Pilot |
|
| |
Adjustment |
| ½ NPT | |
(Remove Cap) | |||
(Outlet) | |||
| Pilot | ||
|
| ||
| Gas |
| |
| Connect |
| |
Figure 16: Two Stage Gas Valve Front
3.To increase the gas pressure, turn the adjusting screw clockwise.
NOTE: The correct manifold pressure for natural gas furnaces is 3.5 IWG high heat and 1.5 IWG low heat. The correct manifold pressure for propane (LP) is 10.0 IWG high heat and 4.5 IWG low heat.
Burner Instructions
To check or change the burners, CLOSE THE MAIN MANUAL
1.Remove the two (2) #8 screws holding each burner in place.
2.Remove the burner assembly from the manifold assembly by moving the burner assembly forward, turn at an angle and pull back.
3.Burners are now accessible for service.
Pilot Instruction
To adjust the pilot flame:
3 8" min.
|
| Line |
½ NPT |
| Pressure |
| ||
| Tap | |
(Inlet) |
| |
|
|
Figure 17: Single Stage Gas Valve Rear
½NPT
(Inlet)
Line Pressure
Tap
Figure 18: Two Stage Gas Valve Rear
Adjust as follows:
1.Remove the cap from the valve body. See Figures 15 and 16 for location.
2.To decrease the gas pressure, turn the adjusting screw counterclockwise.
Spark Ignitor
Pilot | Flame Sensor |
Figure 19: Proper Flame Adjustment
1.Remove the pilot adjustment cover screw.
2.Adjust the pilot adjustment screw to achieve the proper pilot flame.
3.The pilot flame should envelope 3/8” of the end of the flame sensor and not contain any yellow color, see Figure 19.
4.Replace the pilot adjustment cover screw after the pilot flame is set.
To check, adjust or remove the pilot assembly, CLOSE THE MAIN MANUAL
1.Disconnect the wiring from the control board to the pilot assembly.
2.Remove the two (2) #8 screws holding the pilot assembly in place.
3.Remove the pilot assembly.
26 | Unitary Products Group |
