I want to balance my nan's heating system, as there are a couple of radiators which do not get very hot. I have bled all radiators and no air has come out. I have read various guides on balancing which tell you to work out from the closest rad to the boiler to the one furthest away. The pump is actually upstairs in the airing cupboard, however the boiler is in the downstairs toilet. Do I need to work out from the pump, or the boiler? I guess I need to work from the pump in this instance but as I haven't done this before, I would appreciate if someone more experienced could confirm (or not) that this is the case. Many thanks.