Manual background

All installations and services must be performed by qualified service personnel.

Figure 23:

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,

Operating Mode, and Type of Fuel.

Fuel Gas Type

 

Propane

 

 

Natural

 

Operating Mode and

High Fire

CHX Low

CDX Low

High Fire

CHX Low

CDX Low

Model Series

 

Fire

Fire

 

Fire

Fire

Normal Manifold

10.0 ± 0.3

4.8 ± 0.3

5.6 ± 0.3

3.5 ± 0.3

1.8 ± 0.3

2.0 ± 0.3

Pressure (in. W.G.)

 

 

 

 

 

 

Maximum Gas Supply

 

14.0

 

 

14.0

 

Pressure (in. W.G.)

 

 

 

 

 

 

 

 

 

 

Minimum Gas Supply

 

11.0

 

 

4.5

 

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.

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Thermo Products 100n, chx-3 75n, 125n operation manual Figure