Wall mount WC - leak at flush pipe entry to pan

[marshr02]

Anyone help me.

I've removed my wall hung WC to paint behind etc, and when refitting it keeps leaking. The leak is where the flush pipe from the cistern enters the pan. There is a supplied rubber bung that is supposed to seal to the ceramic socket. I've tried refitting about 4 times & still it leaks.

I was going to try some fernox-ls around the pipe before fitting into the rubber bung - any hints or ideas gladly welcomes from the pros..

 

[buffy27]

keep it simple.silicone . let it dry well first.

 

[marshr02]

thanks for the reply. Do you mean silicone, like used to seal bath edge? I thought fernox-lsx was silicone, but better suited to sealing plumbing fittings?

& sorry, do you mean omit the rubber bung or in addition

cheers for any help

 

[Carl86]

Naa mate Fernox LSX is a sealant paste for compression fittings and threaded joints. What you want is a good decent sanitary silicone and a cheap silicone gun, you can get it form all hardware shops like BnQ or plumbing merchants, clean the flush cone and dry the socket in the pan then run a bead round the last 2 seals then refit to toilet wiping any excess makingsure its slealed all the way round when its pushed back into the pan off and let it dry for a few hours so no flushing. Jobs a good one.

 

[marshr02]

Thanks for replies.

Carl, can I ask two more questions

1) As well as running a bead around the outside of the rubber bung - on the last 2 seals, is it also a good idea to run a bead between the rigid plastic inlet pipe and its contact with the inside of the rubber bung

2) Is normal silicone used to seal bath, basin wastes etc? rather than plumbers mate?

cheers

 

[buffy27]

Thanks for replies.

Carl, can I ask two more questions

1) As well as running a bead around the outside of the rubber bung - on the last 2 seals, is it also a good idea to run a bead between the rigid plastic inlet pipe and its contact with the inside of the rubber bung

2) Is normal silicone used to seal bath, basin wastes etc? rather than plumbers mate?

cheers

horse it in there my friendaround the bung inside and out. let it dry a while before putting water through it.

 

[Carl86]

Thanks for replies.

Carl, can I ask two more questions

1) As well as running a bead around the outside of the rubber bung - on the last 2 seals, is it also a good idea to run a bead between the rigid plastic inlet pipe and its contact with the inside of the rubber bung

2) Is normal silicone used to seal bath, basin wastes etc? rather than plumbers mate?

cheers

Yes its just normal sanitary sealant silicone that comes in the tubes used to seal round baths and wates grates etc etc, you will need a cheap silicone gun and like buffy says dont be affraid to let lose with it and let it dry.

You could run a bead round the rigid pipe thats in contact with the seal and smooth it over with your finger so it does'nt dry in blobs. As long as you wipe any excess off when its not dryed when you are done it should be fine just its a bit of a sod when its set because its like a rubber and it takes a bit more getting rid.

Carl

 

[marshr02]

Cheers Guys - I'm going to 'horse it in'

 

[buffy27]

most things need a good horsing every now and then.

 

[stevetheplumber]

Anyone help me.

I've removed my wall hung WC to paint behind etc, and when refitting it keeps leaking. The leak is where the flush pipe from the cistern enters the pan. There is a supplied rubber bung that is supposed to seal to the ceramic socket. I've tried refitting about 4 times & still it leaks.

I was going to try some fernox-ls around the pipe before fitting into the rubber bung - any hints or ideas gladly welcomes from the pros..

if the rubber bung is black rubber ive found nothging works well except a new one there a bit hit and miss from the start
however if its the clear plastic type i prefer plumber mate arund it before you push it in with silicon ive found it can pop out again
if you are going to use sillicon best to silicon the plug into the pan leave to go of and then fit the pan back

 

[NickH]

Dont mean to be contrary but personally I dont ever use silicon to seal things like this. If the rubber ring is intact (new) then the pipe should seal, maybe you might need some seasling paste but thats all. To my mind glueing everything together with silicon is a lazy solution and can lead to other problems, if it still doesn't seal (maybe a cracked pipe) then everything is stuck together and you'll have a job to clean it all of, if the cistern has to be removed in future everything is smothered in silicon. No, its simply the wrong way to do it.

 

[BDS]

not a big fan of tons of sealent either,but thats only my oppinion.

 

[stevetheplumber]

great to see the result of this question gives us all some info be a good idea if everyone tried to post what happends to each question here

 

[marshr02]

Thanks Guys for all the replies. Really useful discussion.

It interests me that the manufacturers proposed install method is rarely available for many plumbing fittings, especially sanitary. For example I understand a compression fitting is designed to form a cold weld between olive & pipework - hence if the materials are clean and not damaged there should be no need for any paste. Although I understand the need for belt & braces, if this is your job & you don't want any call backs..

I prefer the use of as little 'extras' as possible, becuase they could mask the real problem, sometimes for the life of the fittings, or maybe for a year or so.

In this example, the pipe is inserted into the rubber bung (black) by around 40mm. In my case I think it was 4mm short. The ceramic 'socket' that the bung fits into seems to be slightly tapered. By adjusting the waste pipe & fitting a timber stud behind it to ensure it isn't pushed back slightly when fitting the pan the problem seems to have been resolved. I'm quessing the taper (don't think I'm imagining it) does it job in applying compression provided the waste pipe fits to the end.

In the real world, I've spent far too long faffing about - if this was my day job! For me the engineered solution by the manufacturer isn't quite reliable enough, hence plumbers trying to evolve backup methods so they can quickly & reliably move on to the next job.

If my guess of what is happening is correct, then merely detailing this on the installation gumpf would make everyone's life easier and we wouldn't all be wasting time trying to guess a solution.

Cheers

 

[dippy_chik]

I hope it's OK for me to be posting here, because I'm not a plumber, we have exactly the same problem, and it's driving me mad.

There is a very small drip leak from the flush pipe. I think the problem is the rubber bung fits the pipe so tightly that I can't get it to sit right. If I put the bung into the pan, and then put the pipe in, it goes partly in but the bung bunches up, even with a bit of washing up liquid on the pipe. If I put the bung on the pipe it gets pushed a little way up the pipe, so doesn't press against the pan.

If I fit the WC straight to the frame, (with a bit of mdf wedged in to push the pan out to the same distance as it should be) I can push the bung back in once the pan is on, and it's fine, so I think the pipe is the right length. But once the furniture/box is on, there's no way to get to it to push it back in.

It's a new setup, inc new bung, so it should be OK, though obviously I can buy a new bung if that'll help.

I'm a bit wary of stuffing a load of silicone in, because if I don't get it right first time it'll be all glued together and then what'll I do?

 

[stevetheplumber]

I hope it's OK for me to be posting here, because I'm not a plumber, we have exactly the same problem, and it's driving me mad.

There is a very small drip leak from the flush pipe. I think the problem is the rubber bung fits the pipe so tightly that I can't get it to sit right. If I put the bung into the pan, and then put the pipe in, it goes partly in but the bung bunches up, even with a bit of washing up liquid on the pipe. If I put the bung on the pipe it gets pushed a little way up the pipe, so doesn't press against the pan.

If I fit the WC straight to the frame, (with a bit of mdf wedged in to push the pan out to the same distance as it should be) I can push the bung back in once the pan is on, and it's fine, so I think the pipe is the right length. But once the furniture/box is on, there's no way to get to it to push it back in.

It's a new setup, inc new bung, so it should be OK, though obviously I can buy a new bung if that'll help.

I'm a bit wary of stuffing a load of silicone in, because if I don't get it right first time it'll be all glued together and then what'll I do?

thats why plumbers mate is better it never sets

 

[david williams]

new flush pipe cone or insert every time,silicone is a bodge

 

[cletus]

i usually chamfer the end of the flush pipe slightly,then apply a small amount(too much can make it pop out)of silicone grease-not silicone sealant-to the flush pipe.push it in ,job done,never had a problem!!

 

[dippy_chik]

I got a new rubber bung, and it didn't help, same problem. I haven't tried the white plastic sort yet, are they interchangeable? I also got some Plumbers Mait, but I've not tried that yet either. I'm not sure making things sticky is going to help, when it seems to be the sticking causing the problem.

Cletus, what is silicone grease, and where would I get it? Thanks!

 

[cletus]

silicone grease is just a plumbers lubricant for using on rubber seals,o rings ect..can be got from any plumbers merchants.just a thought-are you sure its the flush cone that is leaking?it could be the washer on the flush pipe,just where it goes into the cistern.might appear dry when you have the toilet out ,but it may only leak when toilet is flushed.check the washer and make sure the nut under the cistern is tight!

 

[dippy_chik]

it's a dudley frame with a custom push fit flush pipe, there's no washer to tighten but I'm 99% the leak is at the pan entry. I will try and track down some of the silicone grease and see if that helps. Thanks

 

[marshr02]

Quote "If I put the bung into the pan, and then put the pipe in, it goes partly in but the bung bunches up, even with a bit of washing up liquid on the pipe. If I put the bung on the pipe it gets pushed a little way up the pipe, so doesn't press against the pan. "



I recognise this exactly. It's hard to describe while avoiding sexual innuendos but here goes; the black rubber bung is fitted over the end of the pipe but allowed to overhang a little. The WC is offered up, making sure the bung enters the porcelain hole centrally to avoid prematurely catching. I managed to get an implement to hold the bung in position on the pipe (slightly overhanging) while pressing the WC a little further home. At some point the black bung is partially on the end of the pipe, and partially in the hole - further pressing home the WC means that the above implement had to be removed. The bung still bunched up a little but had sufficient coverage over the pipe and into the socket.

No drips, no silicone mastic or grease, no plumbers mait. Lots of swearing and sweaty faces holding b*** heavy wall hung WC while trying to delicately fit bung as described. Now have the knack.

 

[dippy_chik]

Believe me I am way beyong caring about sexual inneundos!

I tried the silicone grease, but just ended up with the bung sliding up the pipe. I still haven't been able to get it fitted properly.

What sort of 'implement' did you use? I am thinking something forked shaped that I can wedge down either side of the flushpipe and push the bung in with maybe?

 

[marshr02]

I used a 'lateral restraint strap - familiar to builders - essentially a long thin piece of metal. Only needed to hold the bung on one side tight against the pipe to hold in position while pushing home the WC - so no need for a forked type thingy - maybe a long kitchen knife would do the job.

Another approach I thought of is using plastic electricians tape wrapped around the pipe behind the bung prior to pushing the WC home. If sufficient tape is wrapped around then this should prevent the bung from being pushed along the pipe when the WC is fitted...

Hope this help

 

[dippy_chik]

Sorry it's taken me so long to come back to this, but I thought I should let you know that we got there in the end!

I didn't have a lateral restraint strap so we improvised with various bits of wood both down the back of the pan and through the hole cut for the flush pipe. We did it as you described, with the bung half on, half off, and with a bit of trial and error and a great deal of luck, we finally got it right. It's all fine now!

Thank you all for your help