Weil-McLain EGH-105 Control Supplement page 25

VIII
1. Turn off power to the boiler and remove the (RED)
wire from terminal TH of the main gas valve
(Figure 12, item 1). Tape off terminal end of
removed wire and restore power to the boiler.
2. Close manual gas valve (Figure 12, item 2).
3. Check that both leak test valves (Figure 12, items 3
and 4) are closed. Then remove plugs and insert
1/8" NPT hose barb fittings as shown in Figure 12.
4. Attach a U-tube manometer to first leak test valve
(Figure 12, item 3).
5. Open first leak test valve (Figure 12, item 3) and
check for pressure. See NOTICE at right.
6. Close first leak test valve (Figure 12, item 3) and
remove manometer.
7. Attach manometer to second leak test valve (Figure
12, item 4 ).
8. Apply call for heat to boiler and check that
electronic pilot proves.
Figure 12
Leak test procedure
Part Number 550-110-677/0299
CSD-1 control system — Natural gas
Check-out procedure — leak test
For your safety, turn off electrical
power supply before making any
electrical connections to avoid
possible shock hazard.
3
677-11
9. Open second leak test valve (Figure 12, item 4) and
check for pressure. See NOTICE below.
10. Close second leak test valve and remove
manometer.
11. Remove call for heat to boiler. Turn off power to
the boiler.
12. Remove hose barbs from leak test valves and
replace plugs.
13. Replace (RED) wire to terminal TH of gas valve.
14. Open manual gas valve (Figure 12, item 2) and
restore power to boiler.
When checking for pressure at the
leak test valves, it is normal to find a
small pressure reading. If the
pressure continues to rise after
opening the leak test valve, the main
valve seat is leaking and should be
replaced.
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