Hi Bacon; That is a regular
wood cook stove, been around for hundreds of years. They work great , some heat
water, they all hold heat for several hours but that's it. Definitely not a RHM although as max has proved it can be done. Mine is close to 100 years old (so is our house) works great, no water heater now but it had one in the past. We use it every winter , nothing like bread baked in a wood cook stove although i'm thinking a
cob oven would be just as good.