1 rad only get hot hot after hot water is called

[profile50e]

Hi,
1 of my rads only get super-hot when starting up from cold. But once the cylinder is full of hot water, it goes warm-to-hot. Then, if I call hot water via shower/bath, that rad gets hot, but never super-hot again.

Is this a problem with the motorised valve?

Setup is:
Profile 50e
Sealed/pumped system
7 rads, all with TRVs fully open
3-way motorised valve

Thanks.

 

[Rover05]

Try switching off pump and boiler.
Isolate all seven rads.
Then bring on demand with stat and power on the pump, leave the boiler off. INDIVIDUALLY, open and bleed each rad in turn. IE, only one open to the system at a time - which is then bled.
Repeat for all seven.
This method gives the best chance of expelling all air from every radiator and its lines.
After which open all seven as usual and bring on the boiler. The pump maybe a variable speed aswell, try upping the speed (rate).