Siamp diaphragm washer relacement- strange behaviour!

[RichardA]

Dear All,

My cistern started making 'spraying' noises and became slow to fill when flushed. Looked at the diaphragm washer and noticed a split. Bought a new washer and replaced old one. With the new washer, the water flows just fine but the flow won't shut off. Put the old (split) washer back and the water sprays and fills slowly but the flow DOES stop. Gone back and forward several times with same results. The new washer look identical and I can't see anything wrong with it.

Any ideas?

Thanks.

 

[exedon2]

Change valve out for a fluidmaster get the one with brass shank.
Less than £14 life's too short!

 

[townfanjon]

I used to fit the replacement diaphragms but , gave up , some work , some don't in my experience .

 

[Deleted member 120897]

Can’t say I’ve had that many issues, are you sure you’re locking the arm back on properly?

 

[RichardA]

Thanks for all replies. Think I'll replace the valve with a Fluidmaster as suggested. Others have suggested this too. I'd still like to know why the new washer doesn't work. It's pretty simple and it can't be anything to do with the arm because it 'works' with the old faulty washer! Very strange.

 

[RichardA]

Final post - just in case anyone's bothered to take a look. I agree with 'exedon2' that life's too short. But as it takes approximately 1 minute to take the washer off and on I thought I'd play with it a bit. I discovered that these valves work by balancing pressure so some water must be allowed to escape to the 'other' side. I wondered if the tiny spout designed for this purpose was actually doing its job. So i created a tiny hole through the plastic body into the spout (took about 5 minutes). And lo - it works! Maybe they need to manufacture the washers just a little bit different.