Weil-McLain Gold CGa - Manual (Page 58)

GOLD CGa Gas-Fired Water Boiler — Boiler Manual
58
Part Number 550-101-009/0107
• TURN OFF POWER to
boiler at service switch or
breaker.
• Remove base access panel (see
Figure 32, item 4, page 62 for
location).
• Verify inlet gas pressure at gas
valve:
Natural gas — 5.0" w.c. min/14.0"
w.c. max
Propane — 11.0" w.c. min/14.0"
w.c. max
Is gas present at gas valve inlet and
within above range?
Electrical shock hazard — Wherever you see TURN OFF POWER , follow the instructions. Failure to follow
instructions could result in severe personal injury, death or substantial property damage.
No Yes
• Is pilot flame visible through inspection port? • Are main manual shutoff valve and boiler gas valve open?
No Yes
• s TURN OFF POWERs to boiler at service switch or breaker.
• Open main manual shutoff valve and boiler gas valve (per
Operating instructions in this manual). Wait at least 45
seconds.
• Turn on power at service switch or breaker. Allow boiler to cycle.
Does FLAME light flash now?
No Yes
• Boiler should be in
normal operating
sequence.
• Observe operation
until thermostat is
satisfied and blower
has completed its
post-purge cycle.
• Make sure ground wire
terminal is securely fastened
to control module mounting
screw.
• Check the voltage across
main gas valve terminals of
the gas valve.
Is 24 VAC present there?
No Yes
• Check the voltage across
main gas valve terminals of
the gas valve.
Is 24 VAC present there?
No Yes
No
Yes
• Contact gas supplier to correct
pressure or gas supply.
• If the wiring from the
control module to gas
valve is intact, replace the
control module.
• Retest.
• TURN OFF POWER to boiler at service switch or breaker.
• Check flame signal — Detach sense lead from igntion control
(Figure 30, item 8, page 53).
• Connect negative lead of MICROAMMETER to control sense
terminal (Figure 30, item 8, page 53). Connect positive lead of
MICROAMMETER to sense wire.
• DISCONNECT red wire connected to man gas valve terminal of
the gas valve.
• Turn on power to boiler and allow to cycle. As soon as pilot is
burning, the MICROAMMETER should read at least 1.0
microamp.
Is flame signal at least 1.0 microamp?
No Yes
• If the wiring from the
control module to gas
valve is intact, replace the
control module and retest.
• Verify inlet gas pressure at gas valve:
Natural gas — 5.0" w.c. min/14.0" w.c. max
Propane — 11.0" w.c. min/14.0" w.c. max
Is gas present at gas valve inlet and within above range?
No
Yes
• TURN OFF POWER to
boiler at service switch or
breaker.
• Remove base access panel
(see Figure 32, item 4,
page 62 for location).
• Verify pilot gas line is not
kinked, obstructed or damaged
and is correctly attached to
pilot and gas valve.
• Verify pilot ignition electrode,
electrode ceramic and spark
lead wire from control are in
good condition. Spark gap
should be approximately 1/8".
• Correct any above problems,
replacing pilot if burner or
wiring is damaged.
• Reinstall base access panel to
operate boiler for retest after
any changes or corrections.
• If none of the above corrects
problem, then replace the
control module, reinstall base
access panel, and retest.
• Verify pilot burner is securely
attached to pilot bracket, bracket
is securely attached to cross tie,
and there is no corrosion on the
parts which would affect the
ground path for flame sense.
• Verify that pilot flame rod, flame
rod ceramic and lead wire from
control module to flame rod are in
good condition.
• Correct any above problems,
replacing pilot if burner or wiring
is damaged.
• If none of the previous steps
(including replacing pilot)
corrects problem, then replace
the control module, reinstall
base access panel and retest.
CHART 6 — Spark-ignited pilot — FLAME light flashing and POWER light on steady
ALSO — Troubleshooting failure to establish main flame
11c
Troubleshooting — spark-pilot boilers
(continued)