Smells from bathroom pipes and sink when using after a few hours Drainage and wastage systems and plumbing help, advice and answers

[RobM]

Hi (first time poster).
When we've not used the bathroom sink for a few hours and then use it, we get a nasty smell from the bath plughole (i.e. first thing in the morning and after a day at work).

I've used plughole unblocker on the sink, shower and bath, and use hair plug covers in the sink and shower but still get the wiff / smell.

We've not replaced the bathroom but appears the sink connects into the shower, that in turn connects to the bath before the outlet. I know this because sometimes we hear or see water 'glugging' in the shower or bath when using the sink.

The outlet (c2-3") pipe runs into the rain gully for the kitchen extension.
We've had a look and the outlet looks quite clear, apart from being a bit mouldy inside.
The house was empty for about a year before we moved in about 3 years ago.

I'm wondering if it would help to clean all the pipes right through the system? What would I use, just bleach? What's the best way to do this? We could cap the outlet and flood the system.

Any help would be greatly appreciated.

Cheers,
RM

[stoneyboy]

Hi robm
The most likely cause it that when the sink is emptied, a vacuum is created which sucks the water out of the bath trap. Assuming you have a 2” bath trap try fitting a deeper trap.
Regards S

[RobM]

Hi stoneyboy,
Thanks, I appreciate the quick reply and advise.
Is the small trap likely the cause of the smell I've getting from the bath plughole?
Regards,
RM

[stoneyboy]

Hi robm
It may be the combination of a 2” deep bath trap and long waste pipe runs. Fitting a deeper trap may solve the problem but if space is an issue you may have to use a hepv0 type trap.
Regards S.

[RobM]

Hi stoneyboy,
Brilliant, thanks.
Regards,
RM

[RobM]

Hi,

I know it's been a long time to post an update on this topic; however, I've finally managed to take a large cabinet off the wall that was preventing me from removing the bath panel and having a look.

In the photo included, the pipe on the left is the main drain that takes the sink and shower before the bath ties-in.

Do you think the shallow trap is causing the problem?

I also want to replace the click-clack as it's corroded. Looking in my local DIY store there appears to be sets that contain the click-clack, overflow pipe and trap. Would you recommend one of these or getting a separate (possibly deeper) trap? the combined sets I saw don't appear to have very deep traps.

This will be my first attempt at plumbing, I usually stick to electrics, so any help and advice you can give?

RM

[stoneyboy]

Hi robm,
The poor installation of the existing trap is almost certainly the cause of your problems. Looking at the angle it has been installed the is very little depth of water left forming the trap.
You can either replace it with a deeper trap but you will have to cut out the floorboard or fit a new trap - mcalpine make a very neat top access click/clack trap which is fully adjustable. Suggest you use a flexible pipe joiner to connect the trap outlet to the existing waste pipe. It looks like the stub of pipe is coming out of a ring seal T so its angle could be adjusted.
Regards S