/diy/ - Do It Yourself

If you have low cost/free water, you could use an array of TEC.
Just run a heat exchanger from the stove exhaust pipe to the TEC array (one side hot water, one side cool water).
They're extremely inefficient (around 3% real-world performance) so you'll need a few, but they're solid state and you only need to move water and don't have to deal with high pressure gasses and moving parts (except for consumer grade water pumps).
Bonus points, you can just plug it into an existing PV/battery setup.