Radiator.

[cupid04]

It sounds like the radiator in the back bedroom is leaking, yet I've been on my
hands and knees and cant find any damp patches. It seems like the noise is
coming from inside the radiator . Never had this problem before. It's just
the trickling sound is driving me bonkers and for some reason I have to keep
racing to the loo. Any sensible suggestions will be gratefully received.

[jomifl]

Have you tried bleeding it? you won't get a trickling noise if there is no air in it.

[johnk]

As jo says, bleed the rad

[carrust]

It's more likely to be a thermostatic valve problem.

[razza]

In my computer room it does the same,as soon as I bleed it it stops.

[AlBags]

It's usually a little air .. winding it's way through the narrow voids in the rad.
Bleed the radiators!

[cupid04]

Ok, I hear you. The radiator has been bled. It dosen't make any difference.
The only time we usually bleed them is if it's cold at the top and hot at the
bottom, or vice versa. Perhaps it's a gremlin, like the back button! Lol.xx
Thanks.

[AlBags]

It is small bubbles of hot air .. takes a while to accumulate.
Only other thing is slight noise from TRV seat .. when it's just near closing or opening.

[cupid04]

Thankyou everyone. I'll get mr.cupid to do it, wouldn't want to scald my
dainty little hands.