RJH wrote :
On 25/03/2018 17:38, RJH wrote:
Can anyone identify this noise? -

https://drive.google.com/open?id=1o_...flq4qiwX_jS6vh

It's a sort of high pitch metallic rattling, happens all the time, and has
started since I drained and refilled the closed combi system.


Ahem, found the cause - it's the casing of the pressure gauge vibrating
against its plastic cover. Think I'll just leave it for the time being

Maybe push a bit of sponge between the two surfaces, to damp it.