Hydrogen can be used for heating/cooking - the same stinky gas they add to natural gas works fine to alert people to gas leaks by people smelling the leak. The gas piping must be upgraded because hydrogen embrittles some alloys = they break. The gas jets and meters need to be changed. Some places used water gas, but it has been largely displaced by natural gas. https://www.merriam-webster.com/dictionary/water%20gas#:~:text=Definition%20of%20water%20gas,after%20carbureting%20as%20an%20illuminant

The truth is induction cook tops and heat pumps can heat/cook for about the same cost. All houses should be sealed to R2000 sealing and insulation standards and as we get rid of all gas types of heat and use electric we will be far better off.