Installation Instructions
85002
│ Gas Valve 120Vrac VK4115
| 4
Failure to close the bleed screw of the Line Pressure Test Port will cause a severe leakage of gas,
resulting in a fire or explosion causing property damage, serious injury or death.
Table 1 Line Pressure and Combustion Parameters
Gas
Line Pressure (inches w.c.)
CO
2
(%)
CO (ppm)
Max.
Nominal/Desired
Min.
Max.
Min.
Max.
Natural
7
4
10.5
9.0
9.8
175
Propane
11
8
13
10.0
10.8
175
Notes:
1
Combustion calibration must only be performed with the burner operating at maximum modulation rate; when tested at
minimum modulation rate the CO
2
must be 0.4-0.8% lower than CO
2
at maximum modulation rate.
Table 2 Minimum and Maximum Modulation Rates
Model
Min. Modulation Rate (RPM)
Max. Modulation Rate (RPM)
Tx200
1000
7300
Tx200C
1100
6650
Note:
Use Installer Menu setting 2-15 to force the burner to operate at the max. (2-15 =
3) and min. (2-15 = 1) modulation rates; see Section 17.0 DISPLAY MENU GUIDE.
Figure 3 Gas Valve and Venturi Assembly
Gas Valve
Venturi
Throttle Screw
–
used to calibrate
combustion at max. modulation rate
Offset Screw
– used to set
combustion at min. modulation rate;
must remove cap first
(use T40 Torx hex wrench)
Line Pressure Test Port
