dual flush cistern

[zingo1327]

I've had a dual flush cistern fitted ( a little water or a lot of water)but there is not enough water to flush the loo. The guy said it is because I still have a tank in the loft and suggested I move to direct mains water. I had a look inside and the cistern is only 1/3rd full. Should it not be at least 1/2 full or is the guy correct.
thank you in advance

[Vicasso]

Well, I'm not a plumber but it sounds as if the float valve is incorrectly set so that the water inflow is being stopped too early. Take the top off the cistern, flush, and watch the float coming up. Is there some sort of adjustment that can be made by some sort of screw or notch arrangement?

[The Builder]

Oh dear. I'm sorry you've been fobbed off by such nonsense. Being tank-fed (by gravity) just means it'll take a few seconds longer to fill the cistern. It makes absolutely no difference to the flush.
Mechanisms do vary, but it sounds like your float level is set too low.
There will be a float attached to the inlet valve. This cuts off the water when the right level is reached. You probably just need to adjust the float to allow a higher water level.
Adjust until the level is about to go down the internal overflow........ preferably an inch or so below that.

[gingejbee]

My Dad has dual-flush fed from loft-tank which works fine. Think Vicasso has the solution.

[Sipowicz]

When you flush the toilet on a "dual flush" toilet, to get the full flush you should hold the handle down until the flush has finished.
It does sound as though your ball valve needs adjusting to get more water in the cistern, this is quite simple for any average DIYer. It makes no difference wether the cistern is fed from the mains or tank!

[zingo1327]

thanks guys.The problem is that there's no visible float, only 2 enclosed chambers so I'll have to figure out how to adjust the water inlet valve. Thanks anyway

[gsr600]

sipowicz - I thought holding it down gives a half flush - it does on mine ??