34
Part Number 550-142-785/0812
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
12 Troubleshooting
continued
CHART 1
—
Troubleshooting
POWER
light status
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.
Problem is with incoming
electricity. Have licensed
electrician repair circuit.
Replace control module.
Retest.
Boiler should now
operate normally.
Have system checked by a
licensed electrician. If
problem persists, call your
local Williamson-Thermoflo
sales representative.
•
Make sure service switch or circuit breaker is on or
fuses are good.
•
Remove
120 VAC IN
plug (
Figure 23, Item 3
, page 33)
on control module.
•
Using voltmeter, check across top and bottom pins of
120 VAC IN
plug.
Does voltmeter indicate 120 VAC?
No
Yes
No
Yes
No
Yes
Chart
2
Chart
6
TSTAT CIRC
light flashing
Chart
3
Chart
4
PURGE
light flashing
FLAME
light flashing
For insufficient heat or no heat problem, go to
Chart 7
if
POWER
light is on steady, with no other
light flashing.
No
Yes
On steady
(not flashing)
No
Yes
—
Usually indicates reversed 120 VAC polarity if POWER light flashes by itself
—
Is POWER light off?
Is POWER light ...
Flashing
alone
Flashing with
another light
•
Reconnect
120 VAC IN
plug.
•
Remove
120 VAC IN
transformer
PRIMARY
plug
(
Figure 23, Item 2
, page 33) on control module.
•
Using voltmeter, check across top and bottom pins of
PRIMARY
receptacle.
Does voltmeter indicate 120 VAC?
•
Reinstall
120 VAC
transformer
PRIMARY
plug.
•
Remove
24 VAC
transformer plug (
Figure 23, Item 5
,
page 33) on control module.
•
Using voltmeter, check pins of plug.
Does voltmeter indicate 24 VAC?
Replace control module.
Retest.
Replace transformer.
Retest and check for back
feed of voltage from
system wiring.
•
Usually indicates polarity on incoming
120 VAC
power
line is wrong.
• ▲
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?
Chart
5
