Hi! I am not pretending to be profi in heating systems. This is my home heating diagram which I developed during last 10 or so years. There is wood burning boiler. When I burn wood in it then it heats 1.5m3 water in two tanks. Then hot water from tanks, automatically injects to the central heating radiators in the rooms. There is also 150l water boiler for hot water, which heats from the same wood. Even those days, when we have about -20*C, I burn wood once per day and it is enough to have constant 22*C temperature in the rooms and hot water available for bath.