Thermo Pride CHX3-75N Installation And Operation Manual page 49

All installations and services must be performed by qualified service personnel.
b. Turn the inner plastic adjustment screw clockwise to increase, or counterclockwise to
decrease, the gas pressure (and gas flow) to the main burner.
c. Replace the regulator cover screw and tighten it firmly to prevent gas leakage.
d. Referring to Table 5, measure the gas pressure and to confirm it has been adjusted to within
the allowable range. Repeat adjustments (a) through (c), as required.
Table 5 Design Gas Pressures for each Furnace Model Series,
Fuel Gas Type
Operating Mode and
Model Series
Normal Manifold
Pressure (in. W.G.)
Maximum Gas Supply
Pressure (in. W.G.)
Minimum Gas Supply
Pressure (in. W.G.)
13. Adjust the room thermostat so the burner will operate on high fire only.
14. To obtain an accurate manifold gas pressure reading, the main burner must be cycled on and off
several times to stabilize the gas control valve pressure regulator diaphragm.
15. Allow the burner to operate for at least 3 minutes before taking gas pressure readings.
16. Using a pressure gauge, measure the burner manifold gas pressure.
17. If checking the input rate by measuring burner manifold pressure, proceed to step 18. If
measuring the input rate by clocking the gas meter, repeat steps 9 through 11, above.
Figure 23:
Operating Mode, and Type of Fuel.
Propane
CHX Low
High Fire
Fire
10.0 ± 0.3 4.8 ± 0.3
14.0
11.0
43
CDX Low CHX Low
High Fire
Fire
5.6 ± 0.3 3.5 ± 0.3 1.8 ± 0.3
Natural
CDX Low
Fire Fire
2.0 ± 0.3
14.0
4.5