PRESSURE RELEIF

[slippyr4]

i thought PRV outlets had to be metal, since worst case they could be spouting steam at considerably more than 100 degrees?

 

[chrishutt]

Is the roof immediately above the boiler? Or are there intermediate floors? Is the vertical flue independent, or does it use an existing chimney flue?

You may find that a vertical flue (concentric type) for a new room sealed combi boiler will not be acceptable in same location.

 

[namsag]

Chrishutt. where does it say a pressure relief pipe must be visible as it is not classed as a warning pipe. Not doubting you just never seen it mentioned in manufacturers instructions . They give you the recommended routing but other than giving consideration not to soak people with HW no other no no`s are given

 

[chrishutt]

where does it say a pressure relief pipe must be visible

Not sure, off hand. But it stands to reason that the fact of the pipe discharging must be brought to attention of householder in a manner that can't easily be ignored.

You could argue that a tundish could do this, but I doubt whether many householders would notice, let alone be concerned about, a drip through a tundish.

Going back to the poster's original question, if the discharge pipe was connected to soil stack and a tundish was used, you would have drain smells coming into house and the plastic soil stack might not withstand 100 C steam discharge.

In the end it's a matter for the manufacturer to determine, since their instructions override other standards.