You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
LEGEND HEATERS<br />
SERVICE WORKBOOK<br />
LOW GAS PRESSURE SWITCH TEST<br />
LEGEND HEATERS<br />
SERVICE WORKBOOK<br />
CHECK OF IGNITOR<br />
S<br />
T<br />
E<br />
P<br />
RESULTS<br />
19<br />
Low Gas Pressure Switch Test<br />
This switch closes at 5.5” w.c. positive gas pressure on Natural gas,<br />
10.5” w.c. on Propane gas.<br />
Test for 24 VAC from each terminal to ground<br />
If the meter: and then<br />
does not read 24 VAC from either<br />
terminal to ground<br />
check wire connections<br />
between low gas pressure<br />
switch and blower prover<br />
reads 24 VAC from only one terminal<br />
and ground<br />
does read 24 VAC from each terminal<br />
to ground<br />
you have<br />
checked for<br />
proper gas<br />
pressure<br />
switch.<br />
replace switch.<br />
go to step 20.<br />
S<br />
T<br />
E<br />
P<br />
23a<br />
LW/LB<br />
1000<br />
RESULTS<br />
Check of Ignitor<br />
Test for 40-70 ohms resistance through the ignitor’s detached wires<br />
from the upper terminal strip terminals 5 and 6. Ignitor is cold.<br />
If the meter:<br />
then<br />
does not read between 45 and 75<br />
replace the ignitor.<br />
does read between 45 and 75 ohms go to Step 25a.<br />
A.O. <strong>Smith</strong> <strong>Water</strong> Products Co.<br />
Irving, Texas © 1997<br />
38<br />
Service Workbook<br />
Training Department<br />
A.O. <strong>Smith</strong> <strong>Water</strong> Products Co.<br />
Irving, Texas © 1997<br />
43<br />
Service Workbook<br />
Training Department
Change language