Service Manual

3Troubleshooting (continued)

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 150 - 285

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 clockwise to decrease CO2 levels or a 1/4 turn counterclockwise to increase CO2 levels. After performing one adjustment on the valve, follow the Combustion Analysis Procedure on page 32 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 3F on page 32 or replace the gas valve.

Figure 3-2Gas Valve Adjustment: Models 150 - 285

Model 399

Locate the throttle adjustment screw on the top of the gas valve, see FIG. 3-3. Using a screwdriver, turn the screw 1/8 turn counterclockwise to increase CO2 levels or 1/8 turn clockwise to decrease CO2 levels. After one adjustment on the valve, follow the Combustion Analysis Procedure on page 32 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 3F on page 32 or replace the gas valve.

Figure 3-3Gas Valve Adjustment: Model 399

THROTTLE ADJUSTMENT

SCREW

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Lochinvar 150 - 800 service manual Gas valve adjustment procedure, Models 150