Gas Valve Adjustment Procedure - Lochinvar Shield SWR125 Installation & Service Manual

12
Troubleshooting

Gas valve adjustment procedure

If adjustment of the gas valve is deemed necessary, use the
following procedures: (Note: The procedures below are
model specific.)
Models 125 -- 285
Locate the throttle adjustment screw on the side of the
venturi valve (FIG. 12-2). Using a screwdriver, turn the
screw a 1/4 turn clockwise to decrease CO
counterclockwise to increase CO
one adjustment on the valve, follow the Combustion Analysis
Procedure on page 78 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 12H on page 78 or replace the
gas valve.
Figure 12-2 Gas Valve Adjustment: Models 125-- 285
(continued)
levels or a 1/4 turn
2
levels. After performing
2
THROTTLE
ADJUSTMENT
SCREW
DIR #2000586627
Installation & Service Manual
Models 400 -- 500
Locate the throttle adjustment screw on the front of the gas
valve, see FIG. 12-3. Using a screwdriver, turn the screw
1/8 turn CLOCKWISE to increase CO2 levels or 1/8 turn
COUNTERCLOCKWISE to decrease CO2 levels. After one
adjustment on the valve, follow the Combustion Analysis
Procedure on page 78 of this manual to measure the combustion.
If combustion is still not within the specified range, repeat
this procedure. This procedure SHALL 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 12H on page 78 or replace the gas valve.
Figure 12-3 Gas Valve Adjustment: Models 400 -- 500
THROTTLE
ADJUSTMENT
SCREW
DIR #2000586627
79