Geberit wall-hung-pan systems... what's the tube for?

[deano]

The blue-painted, steel box-section, adjustable frame for fixing wall- hung pans, with integral cistern, flush pipe, waste bracket and front (or top) flush plate... Great product, once you've deciphered the unintuitive hieroglyphical installation guide (German text would have been easier, even though I don't speak the language)... not to worry though, install one and you'll never need the manual again!

For those in the 'know' already, I'm curious to learn the purpose of the plastic tube/pipe that runs from the top-front-left-hand-corner of the cistern casing (and is made from the same material as the casing), down the left-hand-side of the frame, bends twice (at 45=B0) and then once (at 90=B0) to emerge through a hole, in the bottom left-hand corner of the blue-painted, steel-faceplate, of the frame. At this point, it appears to be capped with a hinged flap, again of the same material... like the lid on a box of tic-tacs!

The install manual shows this pipe, but doesn't indicate it in any way; the Geberit website is totally useless for product technical info and of the three 'plumber mates' I've asked about this question, none of them have even noticed this pipe before, let alone what its for!

My own personal best guess is that it is a conduit for feeding a tube, connected to an 'air-button' (mounted low or on the floor) through to the flush mechanism, in the cistern above!?

Can anyone shed any light?

cheers, deano.

[BigWallop]

For those in the 'know' already, I'm curious to learn the purpose of the plastic tube/pipe that runs from the top-front-left-hand-corner of the cistern casing (and is made from the same material as the casing), down the left-hand-side of the frame, bends twice (at 45°) and then once (at 90°) to emerge through a hole, in the bottom left-hand corner of the blue-painted, steel-faceplate, of the frame. At this point, it appears to be capped with a hinged flap, again of the same material... like the lid on a box of tic-tacs!

Could it be to let air pass as the cistern flushes and fills? If the lid of the cistern is sealed, then it needs some way of letting air pass in and out of the cistren as it fill or empties.

Just a thought.

The install manual shows this pipe, but doesn't indicate it in any way; the Geberit website is totally useless for product technical info and of the three 'plumber mates' I've asked about this question, none of them have even noticed this pipe before, let alone what its for!

My own personal best guess is that it is a conduit for feeding a tube, connected to an 'air-button' (mounted low or on the floor) through to the flush mechanism, in the cistern above!?

Can anyone shed any light?

cheers, deano.

[Tim Downie]

Hmm, it looks almost like an overflow but the bore looks too small to be useful. (Picture here -

$file/Advantages.pdf)I would go with the air admittance/release theory if the cistern was sealed but why run it to floor level, why not keep it at the top?

In short, dunno. ;-)

Tim

[deano]

-

it doesn't make a water-tight seal, where it enters the cistern... it just pops up through a hole! Which, of course, also means that the cistern is not air-tight either!

Looks like I might have to ring Geberit for an answer :)

[Calvin]

I'm certain that niether of mine has got one. I'm sure I'd have noticed and worried about what to do with it! I don't see it being for an air operated flush plate as it's in the wrong place. The air admitance theory is possible I suppose as it terminates in a position which would probably be concealed by the ceramic and so would not leave a normally visible opening in any decor panels. Mind you there's normally enough openings for air to get in to the void anyway so why bother?

Good luck with the ceramic fitting by the way. It's easy but I found it very stressful, tightening the bolts and waiting for the "tink" which would tell me it had all gone wrong! Looks good and work great now though.

[BigWallop]

$file/Advantages.pdf)>> I would go with the air admittance/release theory if the cistern was sealed

My thinking was, it had something to do with silent filling, and your PDF link says it has silent fill. The air intake / outlet is my best guess also, with that evidence.

[Dave N]

I wonder - could it be an anti-siphoning mechanism for protection in case the lavatory bowl fills up with water following a blockage?

--=20 Dave N

[deano]

Only just checked back on this thread. I still haven't found the answer, I'd telephone Geberit (Ideal Standard) but I can't be bothered to deal with the call-handling system they are likely to have!

Some good suggestions have been posted, but the loose fitting of this pipe, into the cistern (and not air or water-tight) rules them out! Surely this means it could only be for feeding/routing something other than air or water?!

The wall-hung pan, I fitted to this frame, had a hole of about 50mm diameter cast into the bottom of it, just below the waste outlet, and invisible when installed. I'm pretty sure this hole exists to allow the escape of fluids (from a leaking pan connector and/or flush-pipe connection), from the void inside the pan, onto the flooring below. This would make it quickly evident that a leak exists, behind the pan. Without the hole, a leak could go unnoticed for quite some time and would build up within the pan void... not nice if from the waste outlet.

Do all wall-hung pans have such a hole, moulded into their base? It seems that they should! In which case, could it be that the 'mysterious' pipe, being discussed, is there to discharge (some of) the water, from an overflowing cistern, into the void, behind the pan, where it would flow out onto the floor, announcing a problem. Users don't always notice internal overflows. This would also stop water leaking into the bulkhead, where the cistern is concealed.

Could that be what it's for?