In my cottage, I'm looking for possible ways to upgrade the existing HW system. I am restricted to a traditional vented system because I'm not connected to mains water, so water is pumped from a well to a header tank.
Existing System
A traditional vented indirect hot water cylinder in a gravity-fed HW system is heated by a solar water heating array (currently defunct), or by an immersion heater. No mains water available, so system header tank is fed by well pump with electronic control via float switches.
Proposed System
Retaining the gravity-fed HW system design (and well water pump supply), it is proposed to fit an upgraded open-vented thermal store, with an indirect heating coil, with motorised valve switching to switch between input from a wood-burning stove and a solar water heating array (whichever provides the most heat at any one time). The store will have a supplementary immersion heater. The system should provide hot water for kitchen sink, 3 x basins and 1 shower, and underfloor heating for an area of max 15 sq.metres.
My main question is whether it is possible to supply DHW and water underfloor heating from the same thermal store, as DHW would be, I guess, 65deg, whereas underfloor heating might be ?20deg?. Is it possible and how would it be achieved? Has anyone done anything similar?