Toilet cistern syphon/overflow

[mackem]

I've bought a replacement toilet bowl & cistern to replace an existing bowl and cistern which were accidentally damaged. New and old are the same make: Armitage and Shanks close coupled "Charlotte". The old cistern has a standard syphon and separate overflow fitted. The new cistern is supplied without a separate overflow ( nor is there a hole in the cistern to accommodate this ) and what seems to be a standard syphon. I contacted the supplier who said the syphon has a built-in overflow and a separate overflow is not needed. However, when I look at the new syphon it looks identical to the old syphon and I cannot see how it contains an overflow mechanism. How can I be sure that the new syphon does have a built in overflow? Any advice would be much appreciated. Tia

[Rob Morley]

Overfill it and see what happens.

[John]

There is a hole in the syphon assembly, about 4 - 5" up at the front. To check it works, fit cistern etc as normal, allow to fill and then press the ballcock (or whatever you have) down and let it 'overfill'. You should then notice that the water goes down into the bowl. If not FLUSH!! I think it works on water pressure etc at a specific level, we once brought someone a 'sharing' cup back from Cyprus that worked on the same principle, when you poured yourself a drink if you took more than your fair share it all drained away!

HTH

John

[Dave Jones]

Overfill it! and see what happens.

[mackem]

I haven't installed the new stuff yet as I was hoping to determine if I had the correct parts first.

[Rob Morley]

Do you need to install it? I'd just fit the syphon to the cistern and fill it with a bucket or hose.

[Richard Porter]

If the top of the outlet pipe is below the top of the cistern and there's a way for the water to get past/round/through the piston as fast as it can flow in then it's going to overflow into the pan and not onto the floor.

[mackem]

Tried it and it and the overflow does work by draining into the bowl !! Don't know how it works as externally it looks identical to the old syphon that needed a separate overflow. Thanks for the contributions.

[jim.]

You went through the same mental process as me (well appart from the appeal to a N.G) I couldn't, and still can't see how it goes down the pan, there is NO hole as described earlier. The cyphon must be designed to allow the overflow over the top. I had to put mine together and fill it with a hose to convince myself. Mine was an Armiatge Shanks toooo.

jim.

[Mike Clarke]

Any syphon will overflow into the pan if the bend at the top gets submerged. But on many cisterns the top of the syphon is well above the "danger" level. I expect that the top of yours sits below the level of anywhere where water could spill out onto the floor.

[Bob Mannix]

This is a standard procedure (now) to avoid the need for an overflow pipe. You can (as I have done) replace the old high siphons with ones designed to overflow, which are lower (clearly).