Ballcock float valve in hot water header tank - noisy refill

[Rollerball]

Recently replaced the ballcock float valve in the hot water header tank in my attic (the old one was over 20 years old and a bit knackered) - I can't remember the exact model of the replacement but it was pretty similar in appearance to this:

1/2" Inch Part 1 BallCock Float Valve for Toilet Cistern and Header Tank, Water Troughs. Manufactured to BS1212. FREE DELIVERY

Introducing our superior quality replacement ballcock - a versatile, and necessary component for your water management needs. This side inlet fill valve is designed to offer a quick and easy solution for a wide range of applications. Whether you're in need of a ballcock for toilet cistern, a...

www.diy.com

In terms of function the replacement works just fine, however it's a lot noisier than the old one when filling up the cistern. Even if I've only had the hot water running for a few seconds the refilling is very noticeable. Admittedly the header tank is above the bathroom, nevertheless the old valve didn't make anywhere near as much noise.

Is this down to the replacement valve possibly being a cheaper make/model, and if so any recommendations for a quieter replacement please?

 

[CountryFan]

It’s not a header tank and iirc a part 2 valve should have been fitted really unless you installed adequate backflow prevention. Maybe the old valve when new was noisy? What noise is it - high pitched or just hearing it refill?

 

[Rollerball]

It’s not a header tank and iirc a part 2 valve should have been fitted really unless you installed adequate backflow prevention. Maybe the old valve when new was noisy? What noise is it - high pitched or just hearing it refill?

It's not high pitched, it's just the noise of the water refilling. It's just far more noticeable than the old valve.

Not a header tank? What's the name then please?

Also, what's a part 2 valve?

 

[CountryFan]

Not a header tank? What's the name then please?

Cold water storage cistern, or just cistern for short.

Also, what's a part 2 valve?

Part 2 has an air gap. So the part 1 shown in your photo is an older type and was permitted, and still is if a check valve (possibly double type) is installed, can come into contact with the water (no air gap). Part 2 has a filler spout and doesn’t usually come into contact with water if installed correctly (air gap).

 

[Rollerball]

Thanks, appreciate the info. A bit puzzling why the new one is so noisy though.

 

[ChrisJP]

I suspect the old valve had its fill tube dipped below the water surface in the tank. This is now not permitted because of the risk of backflow, so the new valve will just drop water from the valve onto the surface of the water and that's the noise you can hear.

 

[Rollerball]

I suspect the old valve had its fill tube dipped below the water surface in the tank. This is now not permitted because of the risk of backflow, so the new valve will just drop water from the valve onto the surface of the water and that's the noise you can hear.

I see, that makes sense. Thanks.