Radiator only hot at the top

[PickleHead]

I've found lots of advice for radiators that don't work at all but how about ones that only get hot at the top???

The rest of the system is working OK. I've tried bleeding it and I've tried switching off all of the other radiators but it's still only warmish at the bottom regardless of how hot the top gets. This radiator is quite new, it was only fitted a few years ago and is one of the newest in the house, we've never noticed a problem until this year. We did replace the bathroom radiator last year with a larger one plus the flow and return drop down from an upstairs room, could any of this have caused the problem?

I have a Worcester Combi Boiler which I've set at around 1.3 bars when the stystems not running. Does this sound right?

 

[corgiman]

Oh dear sounds like sludge to me

 

[bengasman]

First guess sludge, but could be l/s not set right

 

[Timmyturtle]

Make sure both valves are open,
If they are its probably sludge

 

[corgiman]

heck of an echo in this here forum aint there

 

[Steve__M]

If the lockshield valves are open and it's still cold, then an alternative possible explanation to sludge is that the radiator is too large for the pipes supplying it.