Rads hot at top but not at bottom but no air

[fattony]

Im a little confused here, as I've decorated a room I've always taken the radiator off the wall to decorate behind it etc and when I put it back I've always bled the radiator etc.

Its not something I've noticed before but the rads are piping hot at the top but warm at the very bottom, I've bled every radiator and its made no difference, every radiator has a thermostatic valve.

A while back I read a little about balancing the system, in my great wisdom I turned the thermostatic valve down in rooms which retained the heat well but I also turned down the valve on the other side (this may be where my problem is) my thinking behind it (from what I read) was by closing these valves slightly the radiators which had the valves opened further would get hotter.

As they say little knowledge is dangerous but should the valve opposite side of the thermostatic valve be fully open or partially closed depending how much heat you want from the radiator and why would the radiator be hot at the top but warm at the bottom with no air inside?

Thanks

 

[seco services]

hot at the top cold at the bottom can also relate to crud in the system
sitting on the bottom of the rad.

 

[mickyg]

or general poor circulation. Try turning all others off except this one.

 

[Boilerman2]

Because Heat rises, so the top of a radiator will always be slightly hotter than the bottom, but it shouldnt be noticable, either the crad is blocking with sludge, or the system needs balancing using the lock-shield valves - if you have done a lot of decorating and removed the rads in turn, then you have probably undone all of the balancing done originally, (tip - when removing rads, count howmany turns you haver to make to close the lockshield, so you can open it the same number of turns when replacing the rad!)

 

[fattony]

yep I think I've ruined the balancing of the system, is there a simple guide on how to get it back balanced correctly?

 

[wingcoax]

Open all lockshield valves halfway, check which get hottest, turn these down half a turn and repeat test till all are same temp.

 

[fattony]

Thanks job for the weekend