Troubleshooting – Lochinvar KNIGHT 81-286 User Manual
Page 45

3
Troubleshooting
Service Manual
45
Gas valve adjustment procedure
If adjustment of the gas valve is deemed necessary, use the
following procedure:
Locate the throttle adjustment screw on the side of the
venturi valve (FIG. 3-2). Using a screwdriver, turn the screw
a 1/4 turn counterclockwise to increase CO
2
levels or a 1/4
turn clockwise to decrease CO
2
levels. After performing one
adjustment on the valve, follow the Combustion Analysis
Procedure on page 44 of this manual to measure the
combustion.
If combustion is still not within the specified range, repeat the
procedure. This procedure SHOULD NOT be performed
more than four (4) times. If after four (4) adjustments and
the combustion is still not within the specified range, revisit
the possible causes in Table 3-5 on page 44 or replace the gas
valve.
Figure 3-2 Gas Valve Adjustment