Our heating system which is about 15 years old (pumped, open type), has developed a problem over the last few years whereby the radiators are hot upstairs but the downstairs ones are cool at the bottom.
At first I noticed it only on one, and I took it off and rinsed it out, and although some black sludge came out, I didn't think it to be a significant amount. After putting it back I found no difference.
On checking the other rads downstairs (4 in total), I found one of the others, while not as bad, was also not as hot at the bottom as it should be. I then turned off all the other rads upstairs and down and these two both heated up well.
I discovered that the lock shield valves on all rads were opened up full, but there again they always had been. I've closed down these valves upstairs, (also the one in the hall-way downstairs), so that the rads are not hot at the bottom, to try to balance it a bit better, but has not made much difference. The last thing I tried was to drain the system having circulated it for while with some cleaning stuff I got in the local hardware shop, but still no joy.
Any ideas, could it be a problem with the pump? It seems to be working in the sense that it makes the kind of sound you expect, but whether it's doing what it's supposed to I don't know.
At first I noticed it only on one, and I took it off and rinsed it out, and although some black sludge came out, I didn't think it to be a significant amount. After putting it back I found no difference.
On checking the other rads downstairs (4 in total), I found one of the others, while not as bad, was also not as hot at the bottom as it should be. I then turned off all the other rads upstairs and down and these two both heated up well.
I discovered that the lock shield valves on all rads were opened up full, but there again they always had been. I've closed down these valves upstairs, (also the one in the hall-way downstairs), so that the rads are not hot at the bottom, to try to balance it a bit better, but has not made much difference. The last thing I tried was to drain the system having circulated it for while with some cleaning stuff I got in the local hardware shop, but still no joy.
Any ideas, could it be a problem with the pump? It seems to be working in the sense that it makes the kind of sound you expect, but whether it's doing what it's supposed to I don't know.
