Dual flush WC dribble nightmare

Yellow_Fern

I have a dual flush toilet (third floor in ensuite) that suffers from a constant dribble into the bowl. I tried changing the flush mechanism to a Fluidmaster brand but that has not helped. I then changed the rubber seal, and it still didn't help. What is weird is that even when I shut off the 15mm isolating valve, the dribble won't stop. I also don't understand why the valve seems to determine the pace of the dribble. When the valve is fully open, the dribble is more like a little mountain stream. I would have thought the pressure from the supply line is uncorrelated to the water entering the bowl as the water rests in the cistern before entering the bowl. Does any know why? I also don't understand why the pipes are noisy when the valve is in shut position.

Also, could anyone recommend a high-quality compact toilet that doesn't dribble? I find these cheap WC models are horrendously annoying and incredibly wasteful of water. I much prefer the old reliable types. 

Lenar3556

Fluidmaster is a good flush mechanism and usually solves most toilet flush conundrums. Note: It contains an internal overflow, which allows water to flow into the bowl in the event of the float valve (ball cock) failing.

Given what you describe, I would think check that the cistern fill level is not too high. I.e adjust the float valve to provide for a lower fill level.

If you do decide to change the whole thing, Sonas Bathrooms do a range of decent sanitary ware that is competitively priced. They sell through most builders providers/plumbing merchants.

Yellow_Fern

https://www.boards.ie/discussion/comment/119850805#Comment_119850805

Thanks a lot. I figured out a lot from reading this. It turns out the fill mechanism was never changed. Just the drop mechanism. I played around with the settings and it seems to function correctly. If I do change the fill mechanism, I see there is a lot of models from FluidMaster like those with a brass shank and those with delayed fill. Would you have any thoughts on what is best?

https://www.screwfix.ie/p/flomasta-bottom-entry-fill-valve-1-2/5527f

https://www.screwfix.ie/p/fluidmaster-bottom-entry-delayed-action-fill-valve-1-2/108kj

Lenar3556

https://www.boards.ie/discussion/comment/119856631#Comment_119856631

Either of those is probably fine, the biggest consideration is size and shape - will it fit in your cistern? So just check that.

The better quality ones tend to have a brass tail rather than plastic, but it’s no big deal really as long as you are careful not to over tighten.

Delayed fill is a feature of the valve to delay filling of the cistern until after the flush has finished, and supposedly save some water. I wouldn’t get too excited about it.