Acova Radiators cold at bottom hot at top

[nimh]

I have had all of my radiators replaced at the same time and having done some research tried to balance the radiators because the Acova Radiators I had fitted are cold in the middle bottom and hot at the top, left and right.

Don't think its sludge because the boiler was replaced maybe a year before and there couldn't have been much water in the system once all of the old rads were removed.

There has been some improvement but the lockshield valves are nearly closed maybe one eighth of a turn open and I cant get the middle botttom section hot. The rads left, right and top are very hot.

These are very big rads and hold an awful lot more than the previous rads.

The smaller Acova rads are fine but the biggest struggle.

Is this common or do I close the lockshields even more to a dribble running through?

Also, all of the TRV's are bi directional so some are fitted to the outlet with the lockshield on the inlet. Does this matter?

Thanks in advance.

 

[twgas]

try opening the lockshilds a bit more on one or two rads, to start with, and see what happes.

 

[swbjackson]

To check if there is sludge in the rads try turning them all off bar one. If it's still cold at the bottom middle it's probably sludge. If it heats evenly it's a balancing, pump issue or the boiler isn't chucking out enough heat for the system.

 

[nimh]

Thanks both for your replies. It was my balancing that was the problem. My mistake was to start from the furthest point when all the guidance said start closest to the boiler. Then opened the lockshields of the two that weren't right as twgas suggested and now the radiators are giving off some serious heat.