Plumbers/bathroom fitters, a question about WC waste piping.

Fitting a new toilet at the moment, and for the last couple of days I’ve been having a saga getting the waste watertight. I’m using one of those flexible extension connectors now, with a large jubilee clip over the toilet connection, and it’s still weeping.

The outlet of the new pan is a little lower than the old one, casing the waste pipe to bend up a little. Is this likely to be the root cause of my problem? I realise that there will always be a little water sat there. Is there a clever way of sorting this without having to alter the soil stack to lower the waste, which will be a right faff.

The only other thing I can think of is there is a small crack in the pan. Thanks.

I wouldn’t want the pan waste lower than the soil pipe.

And why are you fitting a new toilet that has a crack in it?

I don’t know there’s a crack in it, it’s new. That’s the only other thing I could conceive is the root of the problem. Wasn’t entirely clear, sorry. .

you abolutelysure it the waste and not the flush pipe.

seen so many badly fitted badly designed seals on the flush pipe its crazy.

Are you sure its not the joint between the cistern and the pan that’s leaking?

As sure as I can be. I’ve gone round the connections with some kitchen roll, and it really seems to be the waste.

edit – and to both of you, it’s a back to wall type with a pipe from a concealed cistern. All seems good.

Loosen screws fixing pan to floor. Put some spacers under there for a few days to get the outlet from the pan higher than the inlet to your soil drain. See if it weeps still. If not, there’s your problem. I really don’t think your waste outlet from the pan should be lower than the inlet to the drain.

EDIT: Oh, back to wall type…there will be height adjustable brackets in there won’t there? Anyway, I’d be trying to get the pan higher than the drain to start with, however you do it.

You have to be careful when fitting the connector that the rubber seal is put on straight and isn’t folded over or creased when installed. Difficult when space is a bit tight I know but if it’s not straight it’s easy to have a leak.

out plumber had a nightmare with a concealed fitting pan we asked him to fit a few years ago. the rememdy was a healthy amount of teh best quality sealant he could find applied to teh waste pipe prior to sliding on the flexible union. then he let it dry before fitting the wc in place.

worked a treat.

You know what Van Halen, my mate, who is a general builder of all sorts of stuff just recommended exactly the same thing!

Robdob, I bought one that’s a tube on the outside which is held in place by a large jubilee clip, thinking that may be the issue originally.

OP, have you replaced the waste connector pipe at the same time as the toilet?

I’ve just replaced our toilet and pipe found the best way was to make sure the connector pipe and flange were pushed fully home onto the toilet outlet then slide the toilet up to the external waste. There should be no increase in angle to the external pipe. If there is you may have a bit of adjustment by removing some of the filler (cement/expanding foam) around the external pipe until it lines up. If it’s way out there is a variety of connections to join them without using a flexy hose which are will no doubt cause you more problems at a later date as they tend to collect waste in the corrugation causing blockages.

If the toilet has a crack in it already I wouldn’t fit it either as cracks tend to spread.

Well, would you credit it, there was a pin-hole leak where the cast in pipe for the flush water connected to the back of the pan! I found it by putting some water, tinted with blue food colouring into the back, and there it was. Glad I tried eliminating all the bits first before going the silicon route.

Just the latest in an ever expanding range of problems with this fit. 😥

no need to jubille clip anything all the fittings are push fit seal pan outlet to waste pipe with plumbmait.. job done never leak agin.. if your waste is higher than outlet though water will sit at the low point and will most likely weep out.. about 2 in a 100 leak through th eporcelain especially on 29 quid supermarket loos..