Megaflow or open vented system

[mysteryman]

The scenario you are postulating is so very unlikely that it is not a significant risk - and is no reason for plumbing equipment in wrongly.

I shall not make any further comment on this, as it has gone away from the OP's questions. It is sad to see incorrect work being advised.

 

[Norcon]

The scenario you are postulating is so very unlikely that it is not a significant risk - and is no reason for plumbing equipment in wrongly.

I shall not make any further comment on this, as it has gone away from the OP's questions. It is sad to see incorrect work being advised.

So your happy with 4 bar pressure or higher to a basin tap with back feed potential to an unvented cylinder?

And where in unvented cylinder manufacturer's instructions does it say the balanced take off cannot supply an ensuite basin tap????

Have you ever plumbed an ensuite in a large property? And do you fit two cold pipe runs?

 

[muggles]

It is sad to see incorrect work being advised.

Indeed it is, and it seems you are very much in a minority in thinking that your way is the right way