Part Number 550-142-302/0520
CGi
SERIES 4 — GAS-FIRED WATER BOILER —
Boiler Manual
53
Troubleshooting — control module lights
11c
CHART 1 –– Troubleshooting
POWER
light status
––
!"!#
––
120
Electrical shock hazard
!K$Z
TURN OFF POWER
Z# @
[$# $
Replace control module.
Retest.
Boiler should now
operate normally.
Problem is with incoming
electricity. Have licensed
electrician repair circuit.
Have system checked by a
licensed electrician.
If problem persists, contact
your Weil-McLain Technical
support.
TSTAT/CIRC
light flashing
CHART
2
PURGE
light flashing
CHART
3
CHART
5
FLAME
light flashing
CHART
4
CHART
6
LWCO
light solid
CHART
7
For insufficient heat or no heat problem, go to
CHART 8
if
POWER
light is on steady, with no other
light is flashing.
Is
POWER
light off?
No
Yes
• Make sure service switch or circuit breaker is on or
fuses are good.
• Remove
120 VAC IN
plug (
Figure
38, Item 3
, page 52)
on control module.
• Using voltmeter, check across black and white wire pins of
120 VAC IN
plug.
Does voltmeter indicate
120 VAC
?
No
Yes
• Reconnect
120 VAC IN
plug.
• Remove transformer plug (
Figure 38, Item 2,
page 52)
on control module.
• Using voltmeter, check across left side top and bottom
pins of transformer receptacle.
Does voltmeter indicate
120 VAC
?
No
Yes
• Reinstall
120 VAC
transformer plug.
• Remove
TSTAT
transformer plug (
Figure 38, Item 5
,
page 52) on control module.
• Using voltmeter, check pins of plug.
Does voltmeter indicate
24 VAC
?
No
Yes
Replace transformer.
Retest and check for back
feed of voltage from
system wiring.
Replace control module.
Retest.
• Usually indicates polarity on incoming
120 VAC
power
line is wrong or has insufficient earth ground.
• %%
• Z
TURN OFF POWER
Z
at service switch or breaker,
then reverse the HOT and NEUTRAL wires entering the
boiler in the J-box.
• Restore
POWER
at service switch or breaker.
Is
POWER
No
Yes
Is
POWER
light . . .
Flashing
alone?
Flashing with
another light?
On steady
(NOT flashing)?
