Radiator Hot at the top, cold at the bottom?!?!?!

[davidgray90]

I have a worcester Bosch 280 combi boiler. I have 10 radiators throughout the house- 3 floors, 3 bedrooms, and have recently replaced all except three of them with brand new ones. In my living room the radiator (which is brand new) in my bay window (i.e. furthest from my boiler) is hot at the top and luke warm at the bottom when I have the heating on. The inlet pipe is red hot and the outlet pipe is luke warm. I have thermostatic valves throughout. I was told by someone who had the same problem to turn off all the radiators except the problem one and increase the water pressure (which I did to 2bar when off- 3 bar when on ) and run the heating to max and the pressure should clear a blockage. This seemed to work because the whole radiator went red hot, no cold spots, and both inlet and outlet pipes went red hot although the boiler kept cutting out and I had to keep firing it up again. However when I turned all the other rads back on and ran the system normally, the probem still persisted. Any ideas?

 

[namsag]

Without going to deep into balancing a system. make sure lockshield valve is fully open
And on the rads closest to boiler turn the lockshields off then just open a quarter to half a turn.