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Jun 21, 2017
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Surrey
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General Plumber
Hi.

Ive been to a numerous amount of jobs which require fixing a common fault, with these kind of air pressure Dual flush valves.

Everytime, the client is having a problem with them constantly flushing.
ive tried cleaning them of scale and cleaning up the rubber seal on the bottom.

I never seem to be able to resolve it and end up replacing it with a new one.#

and just recently i ordered a new one and it didnt even work at all, like it wasnt going down enought to stop the water escaping.


does anyone have any experience with these that know what causes is so i can learn from this?
De2uTa

Ideal Standard SV93467 Pneumatic Dual Flush Valve - Multi-Colour: Amazon.co.uk: DIY & Tools

thumbnail_IMG_1544.jpg
 
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Do they have a built in overflow? I have only encountered constant flushing when the inlets were playing up (broken, incorrectly set, etc) and over filling then emptying through the syphon built in overflow causing the constant flush.

As my name suggests though I am an amateur incase that was the first thing you checked!

I will be interested to see what the actual fault is if not that as we have just had several of these installed in my workplace and I have no experience with them.
 
There are a few causes of constant flushing in this video, again, apologies if this is all basic stuff to you that you have already looked at.

 
I have got similar issues with this type of flush. Sometimes it just keep running into the bowl. I then ordered replacement washers but once changed didn't help at all. I never had an issue with buying and replacing a new one but why would they sell the washers if they don't help.
 
If operated via a bowden cable type remotely mounted flush button then could it also be that the cable is sticking leaving the flush valve open?
 
They are cheap rubbish, I always replace them with a different flush valve. Ideally fluidmaster.

They tend to mechanically fail, so it's not the washers but the actual plastic parts that wear. Don't even try to repair it as you will end up going back.

While the cisterns off replace the fill valve and doughnut washer too.
 
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They are cheap rubbish, I always replace them with a different flush valve. Ideally fluidmaster.

They tend to mechanically fail, so it's not the washers but the actual plastic parts that wear. Don't even try to repair it as you will end up going back.

While the cisterns off replace the fill valve and doughnut washer too.
But the problem is if you have a build in one it's always a pain to change the flush valve with a new one especially where no space is.
 
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If operated via a bowden cable type remotely mounted flush button then could it also be that the cable is sticking leaving the flush valve open?
I had it once the hose had a slight kink and it kept the flush button open so it trickled always through
 
I have got similar issues with this type of flush. Sometimes it just keep running into the bowl. I then ordered replacement washers but once changed didn't help at all. I never had an issue with buying and replacing a new one but why would they sell the washers if they don't help.
Because it is not always the washer.
 
These are the armtage shanks cheap close coupled toilet flush valves. They usually have the two "foot" type push button, one large circular plate and one small white foot, they are rarely found in a concealed cistern as the button would have to be fit in the top of the unit.

You'll mostly see them in new builds and I've seen whole estates with the same problem. Trust me I did toilet repairs for 4 years on bg home care. It's the one flush valve I'd never change a washer on.... through bitter experience
 
These are the armtage shanks cheap close coupled toilet flush valves. They usually have the two "foot" type push button, one large circular plate and one small white foot, they are rarely found in a concealed cistern as the button would have to be fit in the top of the unit.

You'll mostly see them in new builds and I've seen whole estates with the same problem. Trust me I did toilet repairs for 4 years on bg home care. It's the one flush valve I'd never change a washer on.. through bitter experience

The one above is the Pneumatic version not the one with the two feet.
 

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