Glow-worm 85/100-B Boiler and Expansion Tank Flow


21 Apr 2010
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United Kingdom
We have a Glow-Worm 85/100-B Boiler feeding our Hot Water System however it was drained recently and flushed by our plumber however since then whenever the Hot Water is on and pumping there is a constant dribble of hot water into the Feed and Expansion Tank.

I've turned down the temperature on the Boiler to about 75% and it still has a constant dribble out into the F&E Tank.

Does anyone have a manual for the Glow-worm 85/100-B Boiler so I can determine where the Thermostat is so I can check it is okay.

Any other pointers on what the issue may be ?
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You don't describe your system type but if its fully pumped with motorised valves then I suggest that the fault is not with the boiler but almost certainly a circulation/blockage problem causing pumping over.The thermostat phial is in a dry pocket on top front of heat exch.Not much in the way of parts available for this boiler.Get your plumber back or if you feel capable start by checking for blockages around cold feed/open vent where it connects to your system.

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