Short circuit toilet!

[The Other John]

I had a replacement toilet installed 3 years ago - it's a 'bog standard' (sorry!) contract style job with no name from Graham's Plumbing Supplies (a Jewson company). It's dual flush with delayed fill. For some reason the fill is often not delayed so the water starts running into the cistern before the flush valve has fallen to the closed position, so the incoming water goes straight down the pan, managing to keep the flush valve from closing. Before I strip it all down to investigate has anyone here come across this problem and if so what's the cure? From my research the valves appear to be Altech - A207 Fill Valve and B208 Flush Valve. How is the delay achieved?

I see Toolstation sell a delayed fill valve for £9.98 so it's no hardship to replace it if necessary.

TOJ.

[Graham.]

IINAP but I suspect the problem may lie with the flush valve rather than the fill valve. Some of the cheap ones are just a flap without any syphonic action at all. Post a picture of the innards of the cistern.

[The Other John]

I'm not an expert with Dropbox, see if this works:

TOJ.

[harryagain]

Get rid of the stupid, cheap and nasty (fail open) flap valve and install a syphon. (Fails "closed") Especially if you have a water meter.

[The Other John]

Can a syphon do dual flush? We do have a meter which is why we have dual flush.

It doesn't look like a flap valve, the blue cylinder in the middle of the photos rides up and down to flush. It seems to me that both valves, fill and flush, have gone faulty at the same time. The fill doesn't always delay and/or the blue cylinder sticks in the up position. Thinking it might be limescale deposits I put a couple of squirts of kettle descaler in the cistern overnight but it doesn't seem to have made any difference, probably too diluted in a cistern full of water, also it has to be boiled when using in a kettle. Another possibility is the cable operating the flush valve could be sticking.

I shall probably end up replacing both valves just to be on the safe side unless someone here comes up with the solution.

TOJ.

[Dave Liquorice]

+1

I'd expect all those available these days to have that feature but check just in case. It's normally a plug at/near the top of the lifting piston that you remove to enable dual flush.

If you want short flush you let go the handle straight away. The piston drops and when the water level in the cistern falls to that of the hole, air enters the syphon and stops the flow.

Long flush you hold the handle, the piston blocks the hole so air can't enter and the cistern fully empties.

[Graham.]

Confession time, my first push button flush "Pacific" worked arse upwards as it were.

Short press full flush, long press half flush, but we had it 10 years before any of us noticed.

[Graham.]

That is a syphon, isn't it?

I have put Fluidmaster syphons and fill valves in both my toilets and have had no problems with them.

[The Other John]

This cistern can't accommodate a handle, it's flushed by a split button in the lid.

TOJ.

[Gefreiter Krueger]

Why do toilets have syphons anyway? I thought the idea of a syphon was = to take water up higher, then back down again. That's not required with= a toilet, as the cistern is directly above the bowl.

-- =

A great way to lose weight is to eat naked in front of a mirror. Restau= rants will almost always throw you out before you can eat too much.

[Apellation Controlee]

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A siphon also prevents leakage. Can be important if you are on a water meter.

[Gefreiter Krueger]

I see, although when they were invented we were more civilised and didn't have water meters.

[Apellation Controlee]

Indeed.

[dennis]

They were invented because the owners of the original loos would prop the handles up and run the water 24x7 and the system couldn't cope.

[Gefreiter Krueger]

Why on earth would someone do that? If you want to deliberately waste water, you just leave the sink/bath taps on.