how to fit a close coupled wc so it doen't leak

[tonyjeffs]

My technique is rubbish. Assemble - fit - test - mop up the mess Reassemble - fit -test - mop upthe mess Repeat until luck improves.

I've just had the same lack of succes on the new under stairs wc that I've built. I don't know what I'm doing wrong. Maybe its that spongy big coupling washer - or maybe it's the seal between the flush assembly and the ceramic cistern. I'll go back and check when i've finished sulking.

I put a smear of silicone around the nuts and washers thinking it might help. Perhaps i shouldn't. Could anyone give me pedantic step by step instructions please?

And ditto the small sink waste. Can't do it first time. Plughole, waste/connection to trap. ***** slight drip from that too :-(

Many Thanks...

Bad mood! Tony

[RobertL]

I found that it was very important that the cistern and loo were properly aligned otherwise the spongy washer does not seal. For example, if the loo sits on a slightly sloping floor, for example, and the cistern is upright then you can get leaks (I did anyway).

I'd smear the spongy washer with vaseline so it can get itself in a comfortable position.

You say you aren't sure if its the spongy washer or the flush mechanism that leaks. If it's the washer then it will only leak when the thing is flushed surely.

Robert

[tonyjeffs]

Good bit of logic - Why didn't I think of that?

- It's definitely the washer. It is all well aligned, though. Maybe the washer slipped - I'll check

-- and I'll apply some vaseline.

I feel a bit more confident

Thanks Tony

[John Rumm]

I used silicone grease rather than sealant - keeps a seal but without setting. (CPC sell it in small tubes - handy to keep one in the plumbing bag for plastic / rubber lubrication).

Not really had much problem with these. Grease and fit donut, plonk cistern in place and do up the screws. Make sure you have the blanking plugs in any places you need them (like the alternative base entry position for the filler).

Now these (especially if the poncy chrome ones) can be a right PITA to get sealed. Make sure all bits are assembled in the right order with all rings, washers and sleeves greased. Do up tight (you may need to use water pump pliers to nip up the rings rather than just hand tight)

[Dave Plowman (News)]

If the cistern is attached to the wall and the pan to the floor they have to be pretty square for the seal to work - can you try assembling the two before fixing them down and see if things line up properly? Old houses are often miles out as regards things being square.

They don't proved a seal - just clamp the two items together.

Did you bed the waste into the sink with plumber's mate or similar? Ceramic sinks near enough always need this as they aren't very accurately made.

[Rod]

Not entirely sure I would endorse Vaseline for this purpose. If the washer is rubber, doesn't Vaseline affect many rubber products? I used thick silicone grease for similar purposes.

Any opinions? Maybe the rubber will not get affected, or it is not rubber, or the scale of the effect is minimal?

[John Rumm]

It will perish natural rubber. Chances are the foam is synthetic, but I always use silicone grease to be on the safe side.

[Pete Verdon]

It certainly eats bike inner tubes. I used it to grease an educational apparatus that used strips of inner tube to provide elasticity, and they all perished in a couple of weeks.

Pete

[Pete Verdon]

Here's the contraption:

strange-looking man in the picture is the creator, I merely designed and built it for him.

Pete

[The Medway Handyman]

Close coupled WC's leak in one of two places. The joint between the syphon and the cisterm or the joint between the cistern & the bowl.

Fit the syphon to the cistern with a liberal application of LSX. Ignore any idiot instructions such as 'sealant is not necessary'. It is.

Fix the bowl to the floor, but don't tighten up the fixings holding the cistern to the wall untill you have done up the nuts & washers holding cistern to bowl. If leak persists, remove cistern & apply liberal amount of Plumbers Mait around donut washer.

LSX is your friend. But bear in mind waste systems need to be perfectly lined up to seal.

Plumbing aparatus is by & large designed by morons IME.

[jsabine]

Heh. Sounds all too familiar.

Sometimes, depending on how daft the designers are, they also leak from the holes for the bolts fixing the cistern to the bowl.

Very often, it is not necessary. However, you only find out whether it was or wasn't after the assemble/fit/mop process ...

Or, if you're not too fussed about ease of disassembly, silicone or CT1.

And also bear in mind that LSX skins over and won't stick if there's even a hint of water on the surface. CT1

has entirely replaced LSX in my affections. It's a bugger to track down a supplier though.

They really ought to be made to assemble and fit their designs in half a dozen real-world installations before the products are sold. Same with light fittings.

[Andy Dingley]

Which bolts are they? I don't think I've ever seen a cistern that had such a thing. Aren't they always attached to the fabric of the room separately, then the only thig with "bolts" is a steel clamp plate that's pulled down onto the pan so as to crush the doughnut and squirt it sideways, thus sealing against the syphon outlet.

[The Medway Handyman]

Quite common. You get both the 'steel plate design and the 'holes through bottom of cistern' design. The latter has 2 SS bolts & cone shaped rubber washers. They go right through the cistern & pan and are done up underneath.

Yes I know.

[jsabine]

Quite often seen in cisterns that have been supplied with a plastic liner. All fine and dandy - except that the fixing bolts go through the liner as well as the cistern ...