Noisy CB24 Diverter valve ?

18 Feb 2021
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United Kingdom
Hi all, I would appreciate comments from those more experienced in boiler repairs

After several years the replacement diverter valve in my CB24 boiler packed up due to leaking diaphragm , so no hot water - I bought a diaphragm repair kit from an eBay supplier but it never came so still no hot water

I went to local heating supplier but when I eventually managed to make myself understood it turned out they didn't have any repair kits, they offered me a refurbished diverter valve which I bought - today I installed it only to find that although I have hot water, the diverter valve screams when passing more than a small flow - I have not come across this before and I can't help wondering if all is not well with the refurbished valve ?

Any constructive comments gratefully received
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Yes my CB24 includes a seasonality valve but it has not been touched before or since changing the DHW diverter valve and back when the diverter valve was first changed X years ago there was no similar problem with noise from the valve which is why I am having doubts about the workmanship that went into "refurbishment".

The noise is similar to that from a tap with loose washer - the diverter valve breaks into a squeal when the hot water tap is opened more than for a gentle flow
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Run the water and when the noise starts adjust the seasonality valve (you can always turn it back to what it was) and see if this changes the noise, just a small screw at the front to adjust it

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