HELIX VX-399 Installation, Operation & Maintanance Manual page 37

FIGURE 9-4 Offset Screw Location - 399 MBH
White Plastic
Offset Screw Is
Located Under The
Aluminum Cap
9 - START UP PROCEDURE
Gas
Natural
Gas
Propane
4.
See Figure 9-4 for location of Offset Screw on
modulating gas valve of various boiler models. T40
male Torx bit is necessary for removal of Offset Screw
cap and adjustment of Offset Screw.
5.
Set boiler to High Power using System Test to confirm
combustion in High Fire (Step 2).
6. Combustion setting is now complete.
A. Exit System Test mode by pushing Enter. High
B. Scroll down to "OFF". Push Enter button "OFF"
C. Push Menu button twice to escape Installer Manual.
7.
Check ignition quality 4 times with front jacket off.
Close internal manual gas valve for 5 seconds and then
re-open it. Boiler will go through post purge – prepurge
– ignition sequence. Reset boiler if boiler goes into
lockout.
8.
Check ignition quality 4 times with the front jacket on.
Close the external gas shutoff valve for 5 seconds
and re-open it. Boiler will go through a post purge –
prepurge – ignition sequence. Reset the boiler if boiler
goes into lockout.
37
LOW fire combustion - 399 MBH
CO2
Design
Min Max
Target
8.8% 9.2% 9.0%
9.8% 10.5% 10.0%
Power will start flashing.
stops flashing.
Boiler returns to CH mode or DHW mode depending
on type of call for heat available.
Flame
signal
CO
μA
<100ppm >4.5
P/N 240010943, Rev. C [09/07/2016]