HepVo and discharge from unvented cylinder

[Winco]

Hello

The following pdf document states that you can discharge from an unvented hot water cylinder, via a HepVo into a soil stack.

http://www.nhbc.co.uk/NHBCPublicati...ical/StandardsExtra/filedownload,34921,en.pdf

The pdf document states:
"Discharge pipework must not be used for other purposes. Don't be tempted to connect sink wastes, washing machines wastes or condensate pipes to the discharge pipe. This is to ensure the pipe never becomes blocked."

The pdf document shows a vertical soil stack.

Question 1: Can I connect my discharge pipe to a 2m long horizontal branch from my soil stack and also have a boiler condensate discharge into same horizontal branch?

Question 2: If question 1 is yes, could the horizontal branch be 50mm and not 100mm?

Question 3: so long as there is a form of indication that it is operating because of a system fault, could the prv from a boiler be fed into the same horizontal branch?

 

[Agile]

Generally yes to all those questions as far as you have asked them.

However, the installatrion/modification of an unvented should be done by a qualified person and in accordance with all the rags which are applicable.

Tony

 

[powell30]

This is a DIY forum but forum rules prevent us offering advice on restricted trades issues. As Tony has pointed out this installation needs to be completed by an engineer with a G3 ticket......or you won't get the buildings control sign off

 

[Winco]

powell30.......

I do understand that and abide by that by using a tried and tested plumber who has the unvented ticket. However, my tried and tested plumber never told me about the HepVo option, but there again, he has not put in as much layout thought as I have. So , my questions on this forum are as a result of my research so that when I discuss with my plumber, what I suggest to him is predominantly valid, and he does not have to waste time with invalid thoughts from me.

 

[muggles]

Besides the G3 bits mentioned above, the TPRV pipework from the cylinder MUST be run in high-temperature-rated waste pipework (rated to over 100ºC), normally this is MuPVC. Standard waste pipe is not permissible as it could melt in the event of a discharge caused by excessive temperature.

 

[Axel]

in accordance with all the rags which are applicable.

I prefer to use towels; they are more absorbent.