49
Part Number
550-110-290/0219
CGt
GAS-FIRED WATER BOILER — Series 2 —
Boiler Manual
Troubleshooting — control module lights
12c
CHART 1 –– Troubleshooting
POWER
light status
––
Usually indicates reversed 120VAC polarity if POWER light flashes by itself
––
120
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.
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, call your
local Weil-McLain sales
representative.
TSTAT/CIRC
light flashing
CHART
2
PRESS SWITCH
light flashing
CHART
3
CHART
5
FLAME
light flashing
CHART
4
CHART
6
For insufficient heat or no heat problem, go to
CHART 7
, page 55 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
120VAC IN
plug (Figure 33
, Item 3
, page 48)
on control module.
• Using voltmeter, check across black and white wire
pins of
120VAC IN
plug.
Does voltmeter indicate
120VAC
?
No
Yes
• Reconnect
120VAC IN
plug.
• Remove
120VAC IN
transformer
PRIMARY
plug
(Figure 33, Item 2,
page 48) on control module.
• Using voltmeter, check across top and bottom pins of
PRIMARY
receptacle.
Does voltmeter indicate
120VAC
?
No
Yes
• Reinstall
120VAC
transformer
PRIMARY
plug.
• Remove
24VAC
transformer plug (Figure 33
, Item 5
,
page 48) on control module.
• Using voltmeter, check pins of plug.
Does voltmeter indicate
24VAC
?
No
Yes
Replace transformer.
Retest and check for back
feed of voltage from
system wiring .
Replace control module.
Retest.
• Usually indicates polarity on incoming
120VAC
power
line is wrong or has insufficient earth ground.
•
Check grounds to make sure unit has sufficient grounding.
•
▲
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
light flashing now?
No
Yes
Is
POWER
light . . .
Flashing
alone?
Flashing with
another light?
On steady
(NOT flashing)?