Instruction manual

Part number 550-142-056/0411
79
GWC gas-fired water boiler — Boiler Manual
Troubleshooting (continued)
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 Williamson-Thermoflo
sales representative.
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.
TSTAT CIRC
light flashing
CHART 2,
page 80
LIMIT
light flashing
CHART 3,
page 81
PRESS SWITCH
light flashing
CHART 4,
page 82
CHART 6,
page 84
FLAME
light flashing
CHART 5,
page 83
CHART 7,
page 85
NO LIGHT IS
FLASHING,
but there is
insufficient heat
CHART 8,
page 86
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 89, page 76, Item 1) on
IBC.
• Using voltmeter, check across top and bottom pins
of 120 VAC IN receptacle.
Does voltmeter indicate 120 VAC?
No Yes
• Reconnect 120 VAC IN plug.
• Remove 120 VAC transformer PRIMARY plug
(Figure 89, page 76, Item 2) on IBC.
• Using voltmeter, check across top and bottom pins of PRI-
MARY receptacle.
Does voltmeter indicate 120 VAC?
No Yes
• Reinstall 120 VAC transformer PRIMARY plug.
• Remove 24 VAC transformer plug (Figure 89, page 76,
Item 7) on IBC.
• Using voltmeter, check across pins of receptacle.
Does voltmeter indicate 24 VAC?
No Yes
Replace transformer.
Retest.
Replace IBC.
Retest.
Replace IBC.
Retest
Is POWER light . . .
Flashing
alone?
Flashing with
another light?
On steady
(NOT flashing)?
• Usually indicates polarity on incoming 120 VAC power
line is wrong.
•
TURN OFF PO
WER 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