Noise when I flush the downstairs loo

casey jones

When I flush the loo under the stairs there follows quite a loud groaning noise in the pipes which lasts about 10 seconds. Everything seems to work okay but I'm afraid this may be a symptom of a problem. This doesn't happen when the upstairs loo is flushed. I checked the attic but the noise is in the downstairs area near the loo itself. Any ideas ?

GreeBo

take the top off the cistern and see if you can identify if the noise is coming from the cistern or somewhere else...
Its a case or trying to narrow it down I reckon...
Also, try stopping the ballcock so no water comes back in to fill the cistern and then flush... might tell you if its a problem with the waste or the feed pipes.

Gandhi

Do they show a TV show called "This Old House" back home? They covered exactly this problem in it about a year ago. Of course, I have completely forgotten how they fixed it.

I'll try doing a search and edit in some useful info when I find it.

<Edit>
Looks like the fill valve was worn. It was letting air in and acting as a foghorn during any change in water pressure. Solution: Replace the fill valve.

Instructions here:

http://www.diynetwork.com/diy/ba_toilets_tubs_showers/article/0,2037,DIY_13715_2273074,00.html
</Edit>

ismynametoolong

It is more than likely caused by air entering the mains piping through a faulty valve probably on the cistern filler . The reason it does not happen upstairs is because the upstairs toilet is normally filled from the tank in your attic and the downstairs is probably filled from the mains .I had the same problem but in an attic conversion filled from the mains due to the tank been at a slightly lower height than the attic toilet . When it happens open the cold tap supply in your downstairs loo and the noise should stop proving this theory !

casey jones

Okay thanks guys that's given me something to go on.

kkennedy

casey jones wrote:

Okay thanks guys that's given me something to go on.