Rocket Mass Heater looped into my current radiator system

I am looking to do a RMH in the next week or so in my basement. the one I'm doing should heat the basement and floor above it, however, I have a 4 story home and don't want to freeze up stairs... a year ago I was looking into boiler stove that would have linked into my current system although the price didn't allow me to go that way with out having to save for a bit. now that its getting cold and I got to do something... I'm hoping to link my current radiator loop into the RMH. I am not sure how it will with expansion tank/pump. Anyone ever do this successfully? can anyone offer me some advice? thanks for any input!

Hey folks,

I want to do something like Kevin. I have a heart for a finnish masonry heater, called firebox. this mass heater should heat, as well as the ground floor, water with copper pipes in the outskirts of the masonry heater.this hot water is send into the return flow of the radiators, straight into the buffer.
this buffer has a heat exchanger for solar panels and provides hot water for radiators and tubes in the walls in the whole house and hot waer for showers. solar in summer, burned wood in winter.
what i am wondering is, how can i avoid steam, but get enough heat for my water storage, without too much electrical control and pump systems. who has built the water heating stoves succesfully safe without to much fancy electric device?
i would love to hear about your experiences. i would also love to build a rocket stove, but in germany i will never get a legal permission. thats because i chose the masonry heater from finland.
thanks for your help.