Radiators releasing heat when valve shut off

[Juman islam]

Hi all,

Today I noticed when the boiler is on, those radiators in the rooms I don't want heating are releasing heat even when the Drayton TRV4 valves fitted onto each of them are turned off all the way to the star symbol.

Does anyone know why this is happening? Could it be due to the extra cold weather today?

 

[ShaunCorbs]

Star symbol is a frost setting so comes on when the room is cold

 

[John.g]

Frost setting is normally ~ 8C so room temperature should be < this for TRV opening. Mine, EPH, can be turned off as well.