CGi Manual
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 hazardTURN OFF POWER
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.
•
•
TURN OFF POWER
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)?