I've just had a new system installed - combi boiler and radiators, to replace my old system from 1970! The two radiators at the end of the system are not working (in the bathroom and toilet upstairs). The one in the bathroom was the only one that was not replaced, as it was a towel rail we got about 3 years ago. The plumber said he cleaned out the system but there could still be debris blocking it, but it might clear itself and start working. Any suggestions gratefully received!