dripping noise from rad

[charlie01]

hi,
there is a dripping noise coming from two of my rads upstairs when the heating is on and its driving me cuckoo. there is no leak but anyone any ideas what it is and how to fix it before i rip it off the wall.
many thanks

 

[Commercial]

could it be air locked in the radiators? Did you bleed them recently?

 

[Hoagy]

Our thermostatic radiator valves make a sort of rattling sound when almost closed.

 

[charlie01]

yes i bleed them every few weeks.
it sounds more of a drip-drip-drip rather than rattling.

 

[DavyJones]

All good suggestions. When you bled the radiator, does air come out?

Pipes can knock where they exit the floor,esp timber floors, the sound travels through the pipe to the rad, may get a bit more noticable when system is off and starting to lose heat slowly.