Williamson-Thermoflo GWC-070 Manual page 83

GWC -
gas fired water boiler
Troubleshooting
CHART 5
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.
• Open manual gas valve.`
• Restart boiler, following Operating instructions on boiler
(see Figure 72, page 64).
• Check for proper operation (per normal sequence of
operation).
• Replace IBC.
• Retest.
• Boiler should now operate normally.
• Original flashing FLAME light caused by igniter not
operating properly.
• See normal sequence of operation (Figure 71, page 63).
• Boiler should now operate normally.
• Original flashing FLAME light caused by gas valve not
operating properly.
• See normal sequence of operation (Figure 71, page 63).
Part number 550-142-056/0411
— Boiler Manual
(continued)
FLAME & POWER lights flashing
Are manual main shutoff valve and gas valve turned on?
No
• Check gas valve harness wires and check for tight wiring connec-
tions on gas valve and IBC. Repair/replace as necessary.
• Recycle boiler by thermostat or service switch (holding power off for
at least 45 seconds).
• Thermostat should call for heat and appropriate zone valves close.
During step 5 of normal sequence of operation (Figure 71, page 63),
• Check and/or replace igniter.
• Recycle boiler by thermostat or service switch. Thermostat should
call for heat and appropriate zone valves close.
• Wait 5 minutes.
• Check and/or replace gas valve.
• Recycle boiler by thermostat or service switch. Thermostat should
call for heat and appropriate zone valves close.
• Wait 5 minutes.
Yes
is there 24 VAC across gas valve terminals?
No
Are FLAME & POWER lights flashing?
No
Are FLAME & POWER lights flashing?
No
• Call your local Williamson-
Yes
Yes
Yes
Thermoflo sales representa-
tive.
83