I recently had my bathroom done which entailed the removal and replacement of the radiator. Since it has gone back on it ticks on and off all night long, but worse we now have ticking in the radiator in my daughters bedroom and it wakes her up...she is six months old. British gas engineer said it was just the metal expanding and contracting but it never used to to it? Worse was to follow and now every radiator upstairs is ticking on and off through the night when the heating is on and it sound like a steel drum band. Needless to say it is doing mine and wife's heads in...PLEASE,PLEASE,PLEASE HELP.