I won;t claim my doubts were calculated. Just a hunch from working on bio-mass boilers recently that you'd be doing rather a lot of stoking to heat a house from a stove. That clearly wasn't factoring in the biomass burner in the sitting room.i forgot about the rads...if they are the priority, what output are they?
to FrankE: i wouldn't argue with you when you say that you doubt it would be feasible, but i am interested in this sort of system for myself so i would ask you to explain the reasons why you have come to that conclusion...
Also I note now you are in France where it's probably a warmer climate (hope so, my next holiday is in France).
Less doubtul then, though I'd defer to the heating guys.