Radiators not warming up

[smaj]

Hi I recently replaced some of my radiators because the bottoms of them were not warming even though we had got someone to do a power flush on them.

After replacing them with some brand new ones we are still getting the same problem.

Its only 4 of them. The rest of them are fine. It seems they are the last to warm up. Is this because they are the furthest away from the boiler?

Even though they have been on for an hour they dont get hot at the bottom like the top

We have bled them to see if there is an air block but there isn't. 

I don't know what to do now and I woukd like as much help as possible. 

Its a large house and I don't fancy another winter in the cold.

Thanks.

 

[gigz]

Turn the other rads off and see if the cool ones start working, if they do its either a balancing problem, pumps weak/undersized or system configurations wrong. Try the FAQ's on balancing first as this is the easiest to fix.