How to Fix Ideal Standard Dual Flush Toilet? (Not Enough Water in Cistern)

SteveVy

Hi I am hoping someone can help me,

In my four bedroom (2 year old house)  I have 4 toilets, out of these 4 toilets only 1 flushes properly. By properly I mean when I use the flush the water that comes out is very powerful.

I checked each cistern and could see the water level in the "toilet that is flushing properly" is much higher in any of the others 3 toilets which is resulting in a "weak flush".

I believe the toilets all have a trevi-universal-univalve-in-line-inlet-valve-237mm-height-bottom-supply- valve, I've tried looking on youtube and the internet and I am lost on how to adjust this so more water goes in to the tank.

So far I have managed to turn the hex screw anti-clockwise (marked in red) which has only increased the water ever so slightly...any ideas how I can get more water into the cistern?

I've felt around and can't seem to find any further adjustments on the inlet valve?

Here is a video of the flush someone else has posted -->

https://www.youtube.com/watch?v=5W70EHUCvlk

grumbler

IMO, it's obvious. You rotate the white plastic screw clockwise (looking from the top) to move it down in order to move the water level up.

SteveVy

Hi Grumbler,

As per my post I've turned the Hex screw clock wise (Circled in red in the photo) as much as it'll go and it's made only a tiny amount of difference...I think there most be something else that needs adjusting.

grumbler

"as much as it'll go" - does this mean that there is no thread remaining above the black float?

Jeepers_Creepers

If you look at the second picture you posted, Steve, the one of the actual valve, you'll hopefully see that the screwed rod - when turned clockwise from above - will pull the black float upwards, hence raising the water level.

It should be as simple as that.

As Grumbler asks, when you say you've done this 'as far as it'll go', what do you mean? Is there any screw thread still visible on that rod above the black float?

If the rod suddenly stops turning whilst there's still thread visible above, unscrew it a bit and check the thread there - are there sprues on it?

SteveVy

.I've adjusted clockwise as recommended as far as I can by hand this has made a little difference but the cistern still needs some more water

SteveVy

Jeepers_Creepers said:

If you look at the second picture you posted, Steve, the one of the actual valve, you'll hopefully see that the screwed rod - when turned clockwise from above - will pull the black float upwards, hence raising the water level.

It should be as simple as that.

As Grumbler asks, when you say you've done this 'as far as it'll go', what do you mean? Is there any screw thread still visible on that rod above the black float?

If the rod suddenly stops turning whilst there's still thread visible above, unscrew it a bit and check the thread there - are there sprues on it?

There is no thread of the screw visible I've turned it as much as I can the head of the screen is now sitting against the black part underneath. I reckon it needs another 2-3 more full turns to get it fill properly...this applies to 3 out of 4 toilets...what is funny is when I look at the toilet that works properly this same screw is only half way tightened yet the cistern fills okay?

Jeepers_Creepers

As Grumbler - and now J-C - have asked, when you say you've done this 'as far as it'll go', what do you mean? Is there any screw thread still visible on that rod above the black float?

If the rod suddenly stops turning whilst there's still thread visible above, unscrew it a bit and check the thread there - are there sprues on it?

SteveVy

Jeepers_Creepers said:

As Grumbler - and now J-C - have asked, when you say you've done this 'as far as it'll go', what do you mean? Is there any screw thread still visible on that rod above the black float?

If the rod suddenly stops turning whilst there's still thread visible above, unscrew it a bit and check the thread there - are there sprues on it?

1) There are no screw threads visible on the rod above the black float since turning it fully clock wise. It is as tight as it'll go.

2) I am unsure on your second question, does spruces mean threads on the rod? if so then I've tightened it all the way to the top past these to the maximum level I can by hand.

grumbler

If the float is in the top position, I don't think you can rise the level any more.

However, there seems to be some 'stop' on the road  - both in one of your pictures above and in this photo below:

https://helpfulcolin.com/repairing-toilet-silent-fill-valve/ -  there are some instructions there ("Adjusting My Cistern’s Water Level"), but they are no different from what was said above.

grumbler

It's possible, that this valve can have different dimensions - for different cisterns.

E.g. this one has 237mm in the name - https://www.plumb2u.com/ideal-standard-univalve-237mm-bottom-entry-_-sv81767-c2x30587337