Lochinvar SNA285-125 Manuale Utente

Pagina di 76
73
12  
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. 12-2).  Using a screwdriver, turn the screw 
a 1/4 turn clockwise to decrease CO
2
 levels or a 1/4 turn 
counterclockwise to increase CO
2
 levels.  After performing 
one adjustment on the valve, follow the Combustion Analysis 
Procedure on page 72 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 12F on page 72 or replace the 
gas valve.
THROTTLE
ADJUSTMENT
SCREW
Figure 12-2 Gas Valve Adjustment: Models 
      
SNR150-100 -- SNA285-125
THROTTLE
ADJUSTMENT
SCREW
Figure 12-4 Gas Valve Adjustment: Model SNA500-125
Model SNA400-125
Locate the throttle adjustment screw on the top of the gas 
valve, see FIG. 12-3.  Using a screwdriver, turn the screw 1/8 
turn  counterclockwise to increase CO
2
 levels or 1/8 turn 
clockwise to decrease CO
2
 levels. After one adjustment on 
the valve, follow the Combustion Analysis Procedure on page 
72 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 12F on page 72 or replace the gas 
valve.
Model SNA500-125
Locate the throttle adjustment screw on top of the gas valve, 
see FIG. 12-4. 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 one adjustment on the valve, follow 
the Combustion Analysis Procedure on page 72 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 12F on page 72 or replace the gas valve.
THROTTLE
ADJUSTMENT
SCREW
Figure 12-3 Gas Valve Adjustment: Model SNA400-125
       
Installation & Service Manual
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