Bathroom sink gurgle

km79

We are in our new build house just over 18 months now and the bathroom sink has developed a gurgle.

There is no issue in terms of the speed the water drains . Once it drains though there is a gurgle straight after (tried to attach video but won’t allow the file type )

So far I’ve tried the following

• removed p trap which was completely clear
• used plunger
• tried the baking soda vinegar solution
• checked the outlet on outside of house (the pipe is sitting flush against the grate but no blockage )

Is my only option now to use drain cleaner ? I’ve used it before in previous houses but am trying to be a bit more careful in this house!

I also cleared the shower hair filter/trap and there was a partial blockage there. They are on different outlets though.

Wearb

If you've an unused bath or shower on the same outlet pipe, make sure their traps have water in them.

I certainly wouldn't start using agressive unblockers when there's no sign of a blockage.

km79

https://www.boards.ie/discussion/comment/121757008#Comment_121757008

Thanks for reply. It is just the shower and sink in that bathroom. Separate outlet pipes. It is a bit of a headwreck more than any big issue yet!

10-10-20

The gurgle which occurs just after a drain/basin has emptied is due to the speed of the water traveling down the pipe (causing suction) and drawing in air past the trap as the water continues it's journey out to the piping just beyond the walls of the house. If it's a problem then it might be an indication that you need an anti-siphon bottle or P-trap which allows a small amount of air through a valve to prevent the trap from being emptied and then gurgling.

Here's some reading on the topic, hope it helps!

https://www.bpf.co.uk/article/new-guidance-helps-clarify-use-of-domestic-air-admittance-valves-1362.aspx

km79

So today I noticed that after the water leaves the outlet pipe outside there is now also a gurgle at that point .

There must be a blockage at some point between P tube and outlet pipe ?

Im pretty much out of options bar getting Mr Muscle drain cleaner . Is it really bad to use that occasionally ? It is likely to happen again though …….

Other option is something like this drain snake from screwfix https://www.screwfix.ie/p/drain-unblocker-7-6m/186xg

i would be worried about the the risk of it getting caught though! The pipes run under and behind tiled floors , screed, block walls etc so I can’t take too many risk (that’s why I was reluctant to use drain cleaner even though if used it for years in old house with no issues )

10-10-20

Try a drain-snake by all means, but if it still gurgles then it's probably what I mentioned.