Cover off combustion chamber boiler fires up no problem, put the cover on and
fan comes on, spark comes on, but no gas, have checked airswitch, flue, fan,
board any ideas would be greatly appreciated boiler is circa 2002

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Mike Putt m
Wrote in message:
Cover off combustion chamber boiler fires up no problem, put the cover on and
fan comes on, spark comes on, but no gas, have checked airswitch, flue, fan,
board any ideas would be greatly appreciated boiler is circa 2002

Are you sure the gas isn't coming on? Seems odd to reach the point
of sparking without gas flow and I can't see why that would be
affected by the cover.

Just a guess but I would check for insulation breakdown on the
ignitor lead (which may be shorting out with the cover
on).

Sniff the exhaust to check if the gas is coming on or not.

Tim

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On 14-Apr-18 7:44 PM, Mike Putt wrote:
Cover off combustion chamber boiler fires up no problem, put the cover
on and
fan comes on, spark comes on, but no gas, have checked airswitch, flue,
fan,
board any ideas would be greatly appreciated boiler is circa 2002


https://www.heatingspareparts.com/bo...-60ss?gid=5140

"Combustion chamber cover"?
Part 24, "retaining plate"
or
Part 40, "main front panel (inner case)"?

Neither part can affect gas flow to the burner. The manifold bolts to
the gas valve and has a jet screwed in at the top that feeds gas to the
burner. The manifold is made from 1/2" steel gas pipe.

I have little experience with G-W sealed systems from this generation
but I see this has a 2 stage modulating gas valve and no pilot. Ignition
is at RHS on main burner and flame detector is via 2 electrodes at LHS.
Burner gets a small pilot/ignition gas feed and it will spark until
flame is detected at LHS of burner, gas flow will then modulate up for
full load.

Check routing and condition of the ignition lead. For each ignition
"tick" you should be able to look in the little window part "41" and see
a spark between the electrode and the burner. If it ticks but you don't
see a spark then it has sparked to ground somewhere else along the
ignition lead. Check the condition and correct fitting of the 40mm
silicon insulation tubes on the ignition electrode and the 2 flame
detector electrodes.