Now we have modulating boilers, out side weather compensation, and apps to turn heating on as we drive home has anyone arranged variable flow temps. to match purpose. ie. >75 C when heating DHW and <65C for underfloor heating. The programme clearly defines the purpose but apart from viessmann 4 pipe setup I'm unaware of any regular boilers with this facility. 1 hour per day in non condensing mode DHW. to ensure boiler is fully condensing, heating, 23 hours seems a reasonable trade off.