radiator problems

[sjrd]

Have a fairly new house nearly 2 years old. Firstly radiator in toilet no longer works at all but i bleed it and it heated up at that moment but not again ever since. Radiator in front room heats up at top only and have bleed this with little or no improvement and the exit side opposite to the side that you set the numbers on is cold. The radiator at top of stairs is the same as the living room but i have not bleed this one. If you can offer advice on what i can do that will be great thanks.

[tamborine]

pumps either not working or not strong enuf for system.

[dave m]

try fernox central heating flush first if no difference could be pump and system is full of gunk,as water is heavier than air,why did it get hot at the top?prob full of gunk,eitha pay for a power flush bout 250,or take each radiator off and flush yor self,as its affecting all rads thats yor prob as rads r on a loop,if yor house is 2 years old you shouldnt need to bleed rads anyway as they have air valves built in

[buildersmate]

Any radiator that heats up only at the TOP only, is a pretty sure sign that there is sludge in the middle towards the base of that rad.
A two year old with sludge is bad news and a sure sign that that insufficient corrosion inhibitor was put into it.
You now need to get the sludge out of it in the way described above, then make sure the proper amount of inhibitor is put into the system.
The gas that forms in one or more of your radiators is not air - it is hydrogen gas - a byproduct of the corrosion reaction that also produces black sludge in the system. Your steel radiators are being eaten alive from the inside-out.

[sjrd]

thanks for all your advice i'll give it a try.