Advice; Hepvo waste valve

[keira01]

Hi, does anyone have experience with fitting a Hepvo waste valve to a pipe which already has a trap (trap is part of the waste). I understand if you do this it "may" cause pockets of air which may slow down the water discharge. This is what the technical dept of Wavin UK told me - I don't know whether they advise this to cover their butt as manufacturers or if it is actually the case.
Any advice would be great - a larger trap cannot be fitted as the pipe is tight up against a joist. I am getting smells and the bath water coming up into the shower (same waste pipe)...

thanks in advance. Denise

 

[Scott_1979]

I've done it before and had no issues.

 

[keira01]

I've done it before and had no issues.

Hi Scott
Did the pipe already have a trap on it like mine (which is part of the waste)?

 

[snowhead]

A Hepvo isn't designed to stop the backflow of water, it's to stop (foul) air.

If the bath water is backing up into the shower, either the pipe downstream of the shower junction is undersized or partially blocked or it has too many restrictive bends.

This would be better than a Hepvo;

McAlpine T28M-NRV Non-Return Valve White 40mm

 

[keira01]

A Hepvo isn't designed to stop the backflow of water, it's to stop (foul) air.

If the bath water is backing up into the shower, either the pipe downstream of the shower junction is undersized or partially blocked or it has too many restrictive bends.

This would be better than a Hepvo;

McAlpine T28M-NRV Non-Return Valve White 40mm

would this also stop the smell as the trap that is currently on it doesn't do the job and I cant fit a bigger one on because the space restriction ....

 

[snowhead]

The smell is most likely the bath water pushing the contents of the basin trap back into the basin.
Stop the movement of water and the smell should stop.

 

[keira01]

The smell is most likely the bath water pushing the contents of the basin trap back into the basin.
Stop the movement of water and the smell should stop.

Ok thank you...and thank you for replying on my other soil pipe smell issue. Ive replied to it. Im having a plumbing nightmare in this new house, i think it was a DIY job and its totally messed up throughout....

 

[Harvest Fields]

I also fit quite a lot of them and also never had an issue.

 

[tolly]

Ive had problems before with 2 traps in series before causing it not to drain. However both traps were conventional water seal ones. Groundworkers had fitted 110mm p traps underground. Then i unknowingly fitted a shower tray with a 40mm trap. The air inbetween the traps stopped it from draining at all. This might be what wavin are referring to. Not sure if ones a hepvo valve it would have the same effect though.

 

[Welder]

Fit anti-vac traps to every basin & bath you can access. This will reduce the opportunities for sucking out the water from the trap due to the poor venting. Make sure the vent is AT LEAST 50mm with NO elbows only 45s.