Pressure relief valve

[Mecca]

Yes a tundish is required within a certain distance from the cylinder. No it can't be pumped, D1 & D2 needs to flow under gravity to the waste/soil/gulley.

Sorry .... your 'read more' link only links to this post.

Ok, thanks for your help. At least this way I get a useful cupboard downstairs.

 

[Madrab]

You're not alone, it is a common issue where a retrofitted unvented is looked to be placed into the same airing cupboard where an open vented cylinder lived and the pressure relief outflow is difficult to achieve as it's invariably located in the middle of the house.

The usual solution to that is a 22/28mm copper pipe being run underfloor, through the outside wall and then down to discharge at ground level.

 

[Mecca]

You're not alone, it is a common issue where a retrofitted unvented is looked to be placed into the same airing cupboard where an open vented cylinder lived and the pressure relief outflow is difficult to achieve as it's invariably located in the middle of the house.

The usual solution to that is a 22/28mm copper pipe being run underfloor, through the outside wall and then down to discharge at ground level.

Concrete floor!

 

[Madrab]

Concrete floor!

Ouch, not good, does make it difficult for sure ..... that being said the discharge pipe height is half way up the cylinder so it could be run inside a wall too, or channel the concrete. Not ideal I know but just running through what other possible options there may be.