Vented wastes

[Jack07]

My bathroom currently feeds into an internal, unvented stack. We've been noticing lately that we're getting a waste odour and I assume that when the toilet, shower or bath discharges waste water it's pulling the water from the other traps?

I hear gurgling from the traps when using the bathroom and the smell is getting stronger. The shower and bath also take ages to clear.

I'm going to replace my basin with a double sink, i thought that i would use the chance to replace the traps for a anti-syphon ones.

Would this help matters and would it be beneficial to fit anti-syphon to both sink traps or would one be sufficient?

We're planning on replacing the bathroom next year so if there's a more substantial fix I can do it then. Would replacing all the traps for anti-syphon help as I can't access the stack.

Regards.

Jack

 

[Madrab]

Possibly ..... If the waste run is clogging up then when draining the water is filling the pipe creating a vacuum behind it. That then pulls the water seal out of the other traps. Using anti Vac traps should help with that but it doesn't sort the main issue which is cleaning the waste run.

Use some detergent and boiling water down the traps and see if that helps too.

 

[lloyda]

I'd have a go with one of these. Solved a similar issue for me. Best £3.60 I've spent in ages.

Drain Blast Unblocker | Toolstation

Injects a high pressure blast of water into the waste pipe.

www.toolstation.com

 

[Hugh Jaleak]

Could well have a blockage down the line somewhere, if the stack is terminated with an AIr Admittance Valve, this effectively seals any positive pressure in the pipework.

If the system is blocked, it is effectively sealed at both ends, so when an appliance discharges, the water going into the stack/drain needs to displace the equivalent volume of air, which looks for the easiest exit. Usually a waste trap, depending on setup.

 

[Jack07]

Thanks for the responses. I've double checked and can't see any blockages in the waste pipe.
I'm going to start with replacing wastes for anti-syphon.
I am able to access the 1½ waste pipe connecting the bathroom suite. So, im wondering if I can connect an inline air admittance valve along the run?
This runs externally to the bathroom so is easily accessed.
If so, is it best to fit it between the last waste and stack?

 

[bsr]

I have two basins and a bath draining into a 40mm waste. Lots of siphoning. I didn't do it! Replacing the first waste in the line with an AAV trap solved the issue for me .

McAlpine Anti-Syphon Bottle Trap White 32mm - Screwfix

Order online at Screwfix.com. Constructed from high temperature polypropylene with compression outlets. Suitable for use with basins and sinks. Neutralises negative syphonic pressure and eliminates gurgling. Multi-fit compression outlet suits waste pipes to BS EN 1451-1-2000. FREE next day...

www.screwfix.com

This was a direct replacement for the existing and took 2 minutes to fit.

 

[Jack07]

I have two basins and a bath draining into a 40mm waste. Lots of siphoning. I didn't do it! Replacing the first waste in the line with an AAV trap solved the issue for me .

McAlpine Anti-Syphon Bottle Trap White 32mm - Screwfix

Order online at Screwfix.com. Constructed from high temperature polypropylene with compression outlets. Suitable for use with basins and sinks. Neutralises negative syphonic pressure and eliminates gurgling. Multi-fit compression outlet suits waste pipes to BS EN 1451-1-2000. FREE next day...

www.screwfix.com

This was a direct replacement for the existing and took 2 minutes to fit.

Cheers, as in the first waste from the stack?

 

[bsr]

Cheers, as in the first waste from the stack?

The one at the end of the run furthest from the stack.