Trap on Unvented Cylinder Discharge

[Ken778]

After having a blocked drain a few days ago (cleared now), I've noticed a slight sewer smell in the house. Our unvented cylinder discharge connects to a HepVo trap however, this seems to be the cause of the smell (pics attached)
It appears that the discharge pipe is pushed right into the HeVo trap holding it open.
Is it ok to cut the pipe back so it just enters the trap but still allows the plastic membrane inside to close?

Thank you

 

[SandyLyon]

The 22mm copper pipe from the tundish into the HepVo valve is far too long, it has probably held the self sealing membrane partly open allowing the foul smell into the property.

The pipe shouldn't intrude into the valve and adaptors are available from Wavin for use with the HepVo.

It may have damaged the membrane and it may not seal properly again. I would put a new one in to be on the safe side or get the original plumbers back as that clearly doesn't meet with the guide lines.

Have a look at this guide in the HepVo guide page 9. http://www.wavin.co.uk/web/download?uuid=a9443f31-058e-4839-bb64-f88b705cba07

 

[Ken778]

Yes, looking in the trap, the membrane now just stays open so I'll need a new one.
I see that I can buy one with a tundish adapter, that seems the best option.

This was done 10 years ago when the house was built, I only bought the property recently!

 

[SandyLyon]

Yes, looking in the trap, the membrane now just stays open so I'll need a new one.
I see that I can buy one with a tundish adapter, that seems the best option.

This was done 10 years ago when the house was built, I only bought the property recently!

NHBC have a 10 year warranty scheme in operation so may be worth trying them.

It's obviously poor installation and a potential (though slight) health risk allowing foul air from the sewer into your home, plus there may be other homes on the estate that have been plumbed the same.

 

[Dan Robinson]

For devices can be used, but that installation is wrong.

Good luck with nhbc though

 

[Nozzle]

Is it even permissible to run that relief into a plastic pipe?

Nozzle

 

[Dan Robinson]

Yea

 

[Nozzle]

Okay, guess I underestimate the capability of PVC pipe then!

Nozzle

 

[SandyLyon]

Okay, guess I underestimate the capability of PVC pipe then!

Nozzle

The regulations are very strict on dimensions, fall, length of run and materials used.

The waste pipe has to be Polypropylene (Pushfit) clipped at no more than 300mm centres and the valve fitted vertically.

See page 9 in link in post #2

 

[OwainDIYer]

Is it even permissible to run that relief into a plastic pipe?

Yes, if the pipe is able to withstand boiling water and is marked as such along its length.

Hotun combines tundish and trap

 

[SandyLyon]

Good luck with nhbc though

Agreed Dan, they are a "difficult" body to deal with.

But as the installation clearly doesn't comply with the agreed / approved method it needs flagging in, assuming that the property is on a new build estate, even if it's only one plumber using that particular practice there could be a number of properties with foul air entering the living areas.

 

[Dan Robinson]

9 years ago they bolted a whole new Estate on the end of ours. Nice big houses marketed as luxury homes for commuters.

A few years ago we were doing up or house when a lady in tears was knocking on my door as NG had cut her off after reporting a smell.

Luckily for her I was ahead of schedule on my ufh and went round.

In the end we had to pull half the kitchen out tracking the gas pipe. In the end we found a bit of 15mm partially sheathed worth leccy tape in contact with the block wall and had corroded through.

At this stage the house was 7 years old.

Nhbc classed it as a fixture and fitting and therefore under the 2 year warranty and told them to go forth.

How a buried gas pipe running through a ceiling and behind a fitted kitchen is a fixture and fitting, God only knows.

 

[Matt887]

9 years ago they bolted a whole new Estate on the end of ours. Nice big houses marketed as luxury homes for commuters.

A few years ago we were doing up or house when a lady in tears was knocking on my door as NG had cut her off after reporting a smell.

Luckily for her I was ahead of schedule on my ufh and went round.

In the end we had to pull half the kitchen out tracking the gas pipe. In the end we found a bit of 15mm partially sheathed worth leccy tape in contact with the block wall and had corroded through.

At this stage the house was 7 years old.

Nhbc classed it as a fixture and fitting and therefore under the 2 year warranty and told them to go forth.

How a buried gas pipe running through a ceiling and behind a fitted kitchen is a fixture and fitting, God only knows.

Sorry to bring up an old thread, but guessing the gas pipe ran behind the plasterboard and wasn't fully encased?