its a build up of mud /dirt in the rad, needs to be flushed out,,you have to take it off the wall , out to the garden , use a garden hose , in one end and wash it out, have the heating off, you have to turn off the valve at each end,of that rad , get a spanner to fit the silver nuts on the rad , open them. there will be water in the rad , get a bin liner bag, to fit under the open vale , drain it into the bag, as a bucket wont fit, lift the rad off the wall. , and out the garden with it, i had to do this with mine, if there is dirt in the middle of the rad , all the bleeding , wont move it, you need to flush it out, it can be a easy job, if there is a little movement in the pipes comming up from the ground,
h, January 2012
