Megaflo: Trouble recharging the air gap

25 Mar 2016
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United Kingdom
I'm having a harder time than I think I should when attempting to recharge the air gap on my Megaflo cylinder.

To make sure I'm doing this right: and I realise to some this will sound like a really basic question, which of these two valves is the cold water inlet to the Megaflo?


I thought it was the one nearest me (the one on the right of the photo). When I turn that valve off, and open the hot tap, only a trickle of water comes off and then no more.
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Great, thanks. One other question: should I expect water to stop discharging from the hot tap and through the tundish at the same time?

When I attempted today, the water stopped from the hot tap very quickly but continued to discharge through the tundish

Edit: I would also add that there is no gurgling sound at all while doing this
Last edited:
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Hateful things. Just fit an external expansion vessel.

Are you sure you're opening the correct valve? It's the one on the cylinder you need, not the one on the pipework

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