Shower not draining with waste cover on

[helix]

hi all,

Had a plumber install pipework / waste etc for a new shower.

Just finished the tiling shower wall and put the enclosure on but for some reason it not drain well when the chrome cover is on the waste outlet.

Without the chrome cover, the water drains fine, but when it is on, the cover seems to get sucked onto the waste outlet as if it is causing a vacuum.

Does anyone have an idea what may be the problem?

Cheers,
Alex

 

[seco services]

have you enough fall on the pipe.

 

[helix]

have you enough fall on the pipe.

It is approx. a 3 metre run from shower to a 90 degree bend outside, then to stack, with bath connected to same waste. The fall is around 60 mm over the three metres.

There is a section where the plumber had to take the waste under a CH pipe and used a couple of 45 degree bends with approx 100mm of pipe inbetween to make the drop, but at an angle, so it drops, but goes sideways as well.

 

[helix]

has anyone else seema a similar issue? Drains fine without chrome cover on, but not with it on.

thanks

 

[SUPERPLUMBER]

i had exactly the same problem with a shower waste cover.

Completely fine with the cover off, but shower starts to fill up with it on.

If the water goes down the shower waste without the cover on then there shouldnt be a problem with the pipework.

Is the shower cover about 4 inches in diameter with a single hole in the top...? the cover fits via a set of radial grooves which click together.

Could it be a design fault?

alternatively you could replace the trap.... or if you wanna diy it maybe drill some more holes in the top...

 

[helix]

Is the shower cover about 4 inches in diameter with a single hole in the top...? the cover fits via a set of radial grooves which click together.

Could it be a design fault?

It's similar, but without the single hole in the top.

Don't think it is a design fault as I bought one of those metal sink strainers today to temporarily put over the waste hole, and although not as bad, the water did not drain well either.

It was like air needs to escape or be sucked into the waste hole for it to drain properly.

 

[seco services]

you say the bath is on the same run.
try running the shower with the bath trap empty of water.

 

[helix]

you say the bath is on the same run.
try running the shower with the bath trap empty of water.

Thanks. Will try tonight when home.

What's your theory?