Lochinvar Gas valve adjustment procedure, Troubleshooting continued, Model SNA400-125

TM

Installation & Service Manual

13 Troubleshooting (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 SNR150-100 -- SNA285-125

Locate the throttle adjustment screw on the side of the venturi valve (FIG. 13-2). 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 68 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 13F on page 68 or replace the gas valve.

Figure 13-3Gas Valve Adjustment: Model SNA400-125

THROTTLE

ADJUSTMENT

SCREW

Figure 13-2Gas Valve Adjustment: Models SNR150-100 -- SNA285-125

THROTTLE

ADJUSTMENT

SCREW

Model SNA400-125

Locate the throttle adjustment screw on the top of the gas valve, see FIG. 13-3. 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 68 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 13F on page 68 or replace the gas valve.

Model SNA500-125

Locate the throttle adjustment screw on top of the gas valve, see FIG. 13-4. Using a screwdriver, turn the screw a 1/4 turn counterclockwise to increase CO2 levels or a 1/4 turn clockwise to decrease CO2 levels. After one adjustment on the valve, follow the Combustion Analysis Procedure on page 68 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 13F on page 68 or replace the gas valve.

Figure 13-4Gas Valve Adjustment: Model SNA500-125

THROTTLE

ADJUSTMENT

SCREW

69