Shower & unvented cylinder installed in bathroom - all gone stinky !!

[wwwebber]

Hi,

Last year we had a shower cubicle installed in our bathroom (it didnt have one before) and it drains into the same waste as the bath. We also had an unvented cylinder fitted (complete with tundish) replacing a vented system. Since then every now and then the bathroom fills full of sewer stink and we cannot work out where it comes from or why. It comes and goes randomly it seems. In the same room is a sink and a toilet.

Any ideas what could be going on ? Thank you.

 

[Ian H]

The stack must be venting into the room or dirty air getting back passed one of the traps.

 

[wwwebber]

The stack must be venting into the room or dirty air getting back passed one of the traps.

The waste shared by the sink, shower & bath enters the main stack on the outside of the building so yes dirty air is getting back in some how but only now and then which is very strange

 

[polesapart]

The discharge from the bath may be pulling the water out of the shower waste trap.

 

[lostinthelight]

What size is the common waste pipe and how long is the horizontal run?

 

[wwwebber]

What size is the common waste pipe and how long is the horizontal run?

Sorry no expert here, its a standard size but it does have quite a long horizontal run internally for about 4 or 5 metres I believe, then it exits the house and connects to the waste. It is this long as it used by the bathroom and shower room. We don't get any smells in the shower room (shower & sink) but we do in the bathroom. The bath is an old roll top bath and its connection to the waste doesn't appear to have a trap. So could it be the horizontal run that is collecting debris and emitting the stink via the bathroom waste ?

 

[muggles]

Have they connected the discharge from the unvented cylinder into the stack without a trap, or with a dry trap which has failed?

 

[wwwebber]

Have they connected the discharge from the unvented cylinder into the stack without a trap, or with a dry trap which has failed?

They used a tundish for this connection I believe

 

[Dan Robinson]

They used a tundish for this connection I believe

But where does it go after the tundish?

I'll opt for the bath pulling the shower trap.

 

[wwwebber]

But where does it go after the tundish?

I'll opt for the bath pulling the shower trap.

Into the sink waste and then into the common waste.

We hardly use the bath and the smells do not coincide when we do use it.

 

[Dan Robinson]

The cylinder should not be terminated like that.


Even with a trap.

 

[muggles]

Into the sink waste and then into the common waste.

There's your problem then - the smells are coming from the tundish

 

[wwwebber]

But doesn't a Tundish prevent this from happening as per the text below ? or do I need a different kind of Tundish ?

"The Tundish is a plastic cup which hooks on to the pressure relief valve. Its job is to catch the drips from the Pressure Relief Valve, and it is also a water trap to prevent any unpleasant odours escaping from the sink waste."

 

[Dan Robinson]

Whoever wrote that is a moron Or talking about a specific product.

 

[Hot&Cold]

"The Tundish is a plastic cup which hooks on to the pressure relief valve. Its job is to catch the drips from the Pressure Relief Valve, and it is also a water trap to prevent any unpleasant odours escaping from the sink waste."

The picturethat comes with that statement,gives a clue https://www.carron.com/faqs/what-is-the-tundish-and-what-does-it-do/