Water drip in tundish unvented cylinder

14 Apr 2010
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United Kingdom
I have an unvented Santon cylinder.

When water is being heated there appears to be a small water drip through the tundish. Is this normal?
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Most unvented cylinders have instructions on them on how to recharge if the air gap has gone, well if its a megaflo. This should stop the drip through the tundish.
the fitting that will be dripping is the pressure/temp relief valve, so its either to hot or as already been stated the expansion vessel/ air gap needs topping up.
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Thanks for all your posts.

Can someont explain how I recharge the air gap on the Santon unvented cylinder
Close the valve that feeds cold mains water to inlet controls of cylinder. Open a hot tap and leave it open. Wait for water to stop coming out. Leave the tap open. Locate the Schraeder valve on the expansion vessel. Use a mechanical 'pen' type pressure gauge to check the pressure. Pump up to 3 bar if required, with a bicycle pump. Put dust cap back on schrader valve. open cold inlet valve. Close hot tap.

Then, look for any more discharge from the T & P tundish. If it continues, get in a G3 geyser geezer.

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