can you still buy toilets with siphon cisterns?

[cantaloupes]

hi,

I hear that a siphon flush is more reliable and water efficient than a valve flush. At our last house we installed a valve flush loo, and it did occasionally stick and continue to flow after the flush. A tap on the button would stop it, but now we are on a meter and don't want this kind of thing happening.

From a cursory look around, it seems most loos now have valve flush,

but it isn't usually mentioned in specs so it takes a long time to find out.

Anyone know of any siphons still out there?

cheers,

rob.

[david ryan]

Well you heard wrong then. The type of flush doesn't control efficiency, it will be the volume of water released during a flush.

You didn't install it correctly.

The specs do give an indication of what type of flush. You don't get a twin flush 3/6litre with two buttons in a syphon type do you?

Lots of them, all you have to do is look.

[Mike Clarke]

Reliability depends on what sort of fault you prefer to have. As a syphon gets older and the diaphragm deteriorates it gets more difficult to get a decent flush and you could end up wasting water with repeated attempts to flush everything away. In the worst case you get no flush at all.

With a valve flush you might end up with a small continuous leak of water into the pan if the valve seal deteriorates or a more dramatic flow if the valve sticks. Probably more of a problem in hard water areas. Either way replacing the valve can generally be done without removing the flush from the cistern which saves a lot of hassle if it's a close coupled one.

Under normal conditions a valve flush is probably more efficient than a syphon since it delivers a full force flush right from the start and it doesn't have to flow through the rather restricted U turn at the top of a syphon. We've just replaced our ageing syphon with an Opella Variflush and it does the job with much less water than before.

[1501]

I recently replaced a syphon with a valve and found it certainly gets rid of the klingons.

[Matty F]

I have a syphon cistern that has never had a diaphragm. There is nothing to wear out. However I wouldn't recommend a syphon as it is not possible to get a half flush, and many visitors have no idea how to flush. For some reason they are unable to simply pull the chain and let it go. No, they pull it many times, giving a small slurp of water each time, until they give up and have to ask for instructions.

The other toilet has a valve flush, and it has always had a tiny leak which seems impossible to fix. I will never buy that brand again.

[John]

Amazing how pople on a DIY group can put up with a knackered diaphragm in the cistern. Not expensive!

[Matty F]

There's a problem with the design of the diaphragm mechanism. It's leaked from new. The diaphragm has a slightly matt finish. Perhaps there's not enough weight on it to stop it leaking. The whole cistern is horrible. I've had to raise it by a few feet to get it to flush properly. A friend had her old cistern replaced with the same brand as mine, and it has the same problems. Next time we will pay extra for a quality design.

[cantaloupes]

...but for a given flush volume, if one type can leak and the other can't, one type will tend to be more efficient

it was a complete cistern from a reputable brand (grohe?), so apart from making sure it was level, there wasn't much to do wrong. I've seen others do this too.

I didn't notice any at plumbworld or victoria plumb, so I was hoping for a hint to avoid trawling every supplier.

cheers,

rob.

[cantaloupes]

i've fitted an interflush/variflush to our existing siphon flush loo, and it seems very good - you can flush with as little or as much as required, seems a very good solution, even better control than 3/6 litre dual flush. It works by letting air into the siphon when you release the lever, aborting the flush.

[Matty F]

Hmm, that's a good idea. I might convert mine to do that. It's in a heritage building so I don't want to put a modern cistern in. Looks like this: