Weil-McLain CGt 2 Series Manual page 52

CGt
GAS-FIRED WATER BOILER — Series 2 —
12c
Troubleshooting — control module lights
–– Usually indicates flame sensed when it shouldn't be there ––
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.
• Leave main manual gas valve closed.
• Turn off power to boiler at service switch or breaker.
• Wait at least 45 seconds.
• Turn on power to boiler.
• Restart boiler, following Operating instructions in this
manual (Section 10c).
Do FLAME and POWER lights still flash?
No
• ▲ TURN OFF POWER ▲
to boiler at service switch
or breaker.
• Open main manual gas
valve.
• Turn on power to boiler
at service switch or
breaker.
• Restart boiler per operating
instructions.
• Perform start-up
procedures in boiler
manual to verify proper
operation.
52
CHART 4 –– FLAME & POWER light flashing
Are manual main shutoff valve and gas valve open?
No
Yes
• Replace control module.
• Retest.
• Allow boiler to continue cycling.
Are FLAME & POWER lights flashing?
No
• Boiler may now be
operating
normally.
• Perform start-up
procedures in
boiler manual to
verify proper
operation.
Boiler Manual
• Turn off power to the boiler at service switch or breaker.
• Wait at least 45 seconds.
• Turn on power to boiler.
• Restart boiler, following Operating instructions in this
manual (Section 10c).
• Look through the pilot inspection port to see if the pilot
is burning during the prepurge period (first 30 seconds
of operation).
Is pilot burning during prepurge period?
No
• Replace gas valve.
• Retest boiler.
Yes
• Boiler should now
• Replace control
module.
• Original flashing
• Retest.
• See normal
120
Yes
Are FLAME & POWER lights flashing?
No
• Replace control
operate normally.
module.
• Retest.
FLAME light
caused by gas
valve not
operating properly.
sequence of
operation,
Figure 27,
page 34
Part Number 550-110-290/0219
(cont.)
Yes
Yes