Siamp connection insecure

[F]

Our close-connected toilet cistern split from top to bottom down one corner(!) recently and dumped the contents, along with the refilling flow, onto the floor and through the ceiling to the dining room lights.

I've replaced it but have had serious problems getting a seal from the copper tap connector to the bottom entry plastic pipe. Taking it off for the replacement tore the fibre washer but, after replacing the washer, I have had constant leaks up the thread of the nut. I've used some PTFE tape around the thread and it's sealed but I would prefer a proper fix.

Anyone able to offer an ideas?

[Andy Burns]

A lick of LSX?

[Dave Plowman (News)]

Getting a good seal on this sort of joint always seems a PITA. Best way is a copper to plastic pipe join below it, so the connection to the cistern is plastic to plastic.

Basically IMHO copper tap connectors rely on going onto a metal thread so they can be tightened till they groan. ;-)

[nospam]

You probably already know this but ... tighten the pipe joint before you tighten the nut that secures the valve to the cistern. This allows the pipe ends to align correctly.

[Roger Mills]

Yes. Replace the fill valve with one which has a metal shank, such as:

[newshound]

+1.

Consider putting in a push-fit tap connector like this.

You can also get them with service valves, although screwfix aren't listing the ones I just used which have nice knurled tap knobs, and a plastic female threaded portion. They came with a tap set and otherwise look rather like JG Speedfit, but the speedfit ones need a screwdriver and have a metal female thread, which I always think is a bit more brutal going on to a cistern type fitting.

Or a squirt of gooey sealant should sort most things out, provided the threads are not completely knackered. I've lent mine out at the moment and can't remember the name, but it looks a bit like this

Loctite 253 or 577 are probably OK too.

[F]

And that was one of the problems! The last slight turn to get the groan was rotating the fill assembly so that it fouled the cistern wall. It took for ever to keep things aligned.

[F]

I didn't know that. I was tightening the valve/cistern nut first to try to avoid the valve assembly rotating as I tightened the pipe joint...

[F]

That looks interesting! Is the diaphragm the same design as those used in the Siamp? I ask because I have a small stock for the Siamp!

If they're not, are they easily available? The Siamps seem to fail fairly regularly.

[DerbyBorn]

Roger Mills wrote in news: [e-mail]:

Are you sure that it is the thread leaking and not the cistern to connector joint which is more likely to leak.

[nospam]

Unless you've damaged the thread in the earlier attempts I'm (fairly) confident that tightening the pipe connector first will solve your problem.

[F]

It was leaking from the thread immediately above the nut rather than from the bottom.

[newshound]

That seems the intuitive thing to do, until you have done a few of them! The nice thing about using a pushfit connection to the copper is that you can rotate that for alignment without undoing anything.

The metal shanked valve suggested elsewhere is also good.

[F]

Is that the 'modern' Boss White? I have Boss White in stock...

[Andy Burns]

Yeah, like a greasy silicone that never fully sets.

[Roger Mills]

Sorry - don't know about spare parts - not needed any as yet. But I wouldn't expect internal parts to be interchangeable between makes of valve.

[spuorgelgoog]

A scrap piece of wood between the fill assembly and the cistern wall to brace the joint whilst tightening might help.

Owain

[Mike Tomlinson]

En el artículo , F escribió:

Try an O-ring instead of the fibre washer. If you get one of those kits of multiple sizes, you'll find one that fits. You only need hand tight plus a quarter turn.

The rubber of the ring gives more easily and forms a seal with the plastic threaded bottom of the cistern inlet valve.

[alan_m]

I fit using a flexi hose which has a thick rubber washer as the seal.

see picture in link

[F]

Thanks, and that's what I've gone with. That and one of the Fluidmaster assemblies. Just looking to get a round tuit now.