Is that a HW tank? I think you need it at 60c to kill any bacteria build up.I did similar last year... Dropped the CH temp from, IIRC, 67oC (which is the "e" setting on the Logic Combi ESP1 35) to 60oC and also the hot water temp to 50oC.
I might try tweaking it a bit to 55/45 CH/HW