I've found a diagnostic code d41 that gives the return temp. this is currently running at 59 deg.
I assume opening the rad valves more will reduce this i.e. letting more flow through the radiator.
However wouldn't having a higher return mean a more efficient system?
Just had the boiler installed but finding it a bit heavy on the gas useage. Any tips as to the best temp setting for the heating. Currently running at 72 with water at 48. Or is it just a case of keep dropping till you feel radiators not heating enough.