Toilet cistern water saving devices.

panda123_2

A technical query here.
the way i understand toilet systems is....... you flush, the syphon uses 6 litres of water, the system re-fills then the ball !!!! cuts the water off when the 6 litres of used water has been replaced.
so if you fit one of these water saving devices in your cistern, (we'll say one litre capacity) the next time you flush only 5 litres of water is taken in. you're saving one litre of water because the device raised the water level by one litre in the cistern.
now the bit which confuses me.........................
all subsequent flushes after the first flush will be back to 6 litres of water being used to refill the cistern because thats the syphons working capacity, 6 litres.
so surely you only make that one flush saving. after the initial flush the toilet goes back to it normal way of 6 litre flush, 6 litre re-fill.
or am i missing something??????????

Cardew

Welcome to the forum.

Not sure I understand.

Forget the first flush.

The capacity of the cistern is 6 litres(at which point the ballcock cuts off the water).

If you put anything(a brick, water saving device etc) with a volume of 1 litre in the cistern, then after 5 litres of water have flowed into the cistern, the ballcock will cut off the water.

You have reduced the capacity of the cistern to 5 litres, so every flush will use 5 litres instead of 6 litres.

If you put in something(brick etc) with a volume of 3 litres. the capacity of the cistern is now 3 litres.

hwalkerh

One thing to watch for is you should use a water saving device in a new style water efficient toilet. i.e a dual flush one or one that does 6litre of less flush.

moonrakerz

hwalkerh wrote: »

One thing to watch for is you should use a water saving device in a new style water efficient toilet.

"Should".......... shouldn't ?

david29dpo

Just bend or adjust and ballcock, its free!

hwalkerh

Oh sorry ...Shouldn't

panda123_2

Thanks, sorted it now. the syphon has a hole in the side where i presume it draws the 'flush' water through. when the water level drops bellow that level it sucks air in through the hole and the flush stops. so the more water you have above that hole, the more water your toilet will flush. Adjusted the ballcock and saved about a litre per flush. thanks. :beer:

2010

I have a brand new toilet just fitted which has a duel flush button, but no matter which button I press the same amount of water goes out of the cistern.
Am I missing something?

david29dpo

Yes, its not adjusted properly.

2010

david29dpo wrote: »

Yes, its not adjusted properly.

On a full flush the cistern completely empties and on a short flush there should be some water (2litre) remaining.
Is this correct?

david29dpo

Sort of. Most i have seen you can adjust the flush on both.