Downstairs toilet change and vanity sink

[Bunkermagnet]

This is one for the real plumbers ( and interent regulation types)..
I am looking at redoing my downstairs toilet, it's just a corner sink and toilet/systern.
Is there any reason why I couldnt replumb the sink waste to feed into the cistern and help reduce water waste and use?
Obviously the flush mechanism will be one of the new flush types with overflow built into it, so there wouldnt be a risk of water onto the floor or flooding.
Has anyone seen this or done it or is there something that would stop it?
Cheers

 

[bigslice]

Aye no bother ?, go for it.i wud think in my limited plumbing knowledge. That u wud end up running the sink just to fill the toilet. Which defeats the purpose .

 

[Bunkermagnet]

Aye no bother ?, go for it.i wud think in my limited plumbing knowledge. That u wud end up running the sink just to fill the toilet. Which defeats the purpose .

My thinking is that you wash your hands after flushing the toilet, so what I would doing would be adding to the cicstern refil rather than straight down the drain.
Thats all that sink is used for, nothing else.

 

[bigslice]

Have a look at grey water systems?

 

[JustOne]

If you reduce the fill on the toilet cistern to just a dribble then by washing your hands you would help the cistern fill.
If you don't however wash your hands the cistern would be filling for 30 mins
At least you'd know who didn't wash their hands

 

[Bunkermagnet]

This is probably more suitable rather than my own creations
toilet/sink combo

 

[bigslice]

Lol i was going to tell u to read up on the laws of gravity but the wc sink combo covers it.


Or does it how much water do u use when washing hands?

 

[jim8flog]

My thoughts would be - gravity - surely the sink outlet would be lower than the cistern inlet so would it work the other way way round with the cistern water going out of the sink waste.
Would probably need some sort of one way valve and may be a pumped system.

Although as said item on the link overcomes this.

 

[Bunkermagnet]

My thoughts would be - gravity - surely the sink outlet would be lower than the cistern inlet so would it work the other way way round with the cistern water going out of the sink waste.
Would probably need some sort of one way valve and may be a pumped system.

Although as said item on the link overcomes this.

I want gravity to help me drain the sink into the cistern, to reduce the fresh water taken in to refill the cistern. Thats my logic and thinking anyway.

 

[backwoodsman]

Just a thought, but I'd check the spec' on the toilet/sink combo carefully before you go that route. The info in the link posted, gives no indication that the sink drains/feeds into the cistern. The only comment they make about "water saving features" relates the dual flush mechanism. I'd be very surprised to find it other than that the sink waste feeds direct into the toilet waste.

If you're going to try it yourself, Jim8flog has the salient point. You will need to mount your sink quite high (relatively speaking). The low point of the sink system (ie the bottom of the trap) will need to be higher than the high point of the toilet system (ie higher than the full level of the cistern). Otherwise gravity will work against you. And you need a bit of height separation to give an appropriate degree of fall in the pipe. Also need to note that the inlet fittings for the cistern will almost certainly be smaller diameter than the waste pipes for the sink. So in all probability, you'll have to have some kind of (unsightly?) Heath Robinson arrangement to get the waste water into the cistern.

 

[rulefan]

As suggested above, the hand basis would have to be higher than the cistern. Probably making it an uncomfortable height. Further draining the basin into the cistern will simply add water to the normal level. It will not reduce the water coming from the main replenishing the cistern normally unless you wash your hands as the cistern is actually refilling.

Post #6 seems to be the best bet unless you have room for separate units. That of course would mean little or no change to the existing plumbing.

 

[Bunkermagnet]

The link I posted didnt drain into the cistern, I used it as an idea. sink drains into cistern.
That is more like it.
Seems Ive found my answer

 

[backwoodsman]

The link I posted didnt drain into the cistern, I used it as an idea. sink drains into cistern.
That is more like it.
Seems Ive found my answer

Seems you've found what you're after.

But if it were me, I'd want to see one "in the flesh" (as it were0. I can't help but think it would be uncomfortable to be reaching across the toilet pan to wash your hands . I think I'd want to give it try before going that way.

 

[Bunkermagnet]

Seems you've found what you're after.

But if it were me, I'd want to see one "in the flesh" (as it were0. I can't help but think it would be uncomfortable to be reaching across the toilet pan to wash your hands . I think I'd want to give it try before going that way.

I have seen one in B&Q ages ago, which is what caught both mine and my wifes eye. It's just a way of redoing our small downstairs toilet, saving some space and saving a little on the water(money) as well.