Williamson-Thermoflo GWC-070 Manual page 85

GWC -
gas fired water boiler
Troubleshooting
CHART 7
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.
• This is NOT a lockout mode. The IBC should only be signal-
ing that the water temperature sensor is either shorted or
there is an open circuit across the sensor terminals.
• Remove SENSOR plug from receptacle on IBC (Figure 89, page 76, Item 6).
• Then re-insert.
• Boiler may now be operating correctly. Verify per normal
sequence of operation (Figure 71, page 63).
Part number 550-142-056/0411
— Boiler Manual
(continued)
LIMIT light flashing and POWER light on steady
• This situation is usually corrected by replacing the sensor,
as described below.
Does LIMIT light still flash?
No
• Replace sensor and harness.
• Replace IBC.
• Retest.
Yes
Does LIMIT light still flash?
No Yes
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