Hi,
bad luck .. so do you at least have a wood-fired oven ?
When we began to build this house we forever thought about which oven/furnace whatever we should buy and install, to be most independent from those "good-willed" gas- and oil distributors, and there were quite some ideas:
1. Buy a wood fired oven, with water filled pipes to support or even exchange the "normal" furnace. You could also buy an "all-burner" or whatever the right expression is in english, and burn all kinds of advertising magazines and papers, newspapers, coal, wood or whatever. You certainly need a fire-proof chimney for this. And you need a hot water buffer reservoir.
Bad part is you will always need wood or something to burn, and electricity for the circulating pump(s). You could certainly use a stirling engine for pumping (driven by the heat of the oven), but i would have to build one myself, nothing on the market.
2. Get a combined heat and power unit (called Block-Heiz-Kraftwerk, or BHKW in Germany), this is being supported in Germany financially, basically an engine which heats water via exhaust (heat exchanger) and produces electricity as a side effect, which is sold and paid for.
The engine is noisy, will have to be maintained, and you also need stuff to run it, but at least you can choose from Diesel, petrol, plant oil, natural or compressed gas, or whatever. You will also need a buffer reservoir for hot water.
If the house is too small, or well insulated, the engine will not run long enough to produce enough electricity to pay off its existence and maintenance costs - but would have been a good idea (house too small and too well insulated - get a warmed swimming pool and heated plastered car entrance against snow in winter, and it will work all the time lol.)
3. Oil or gas furnaces - you are completely dependent on the companies providing it, but it is the cheapest solution to get any furnace.
Oil: You will need stinking storage tanks which take room.
Gas: If anyone decides to cut you off the supply for whatever reason that's it.
4. Geothermal energy - but ... even a hundred meter borehole for a snall one-family house is expensive, and you need circulation pumps (electricity) and a compressor (electricity) to bring the water temperature up to the desired level.
We ended up with a cheap gas furnace (combined hot water and heating system), but big hot-water reservoir supported by solar collectors. The whole thing costed about 5000 Euros, installation of radiators etc. included, but it is quite efficient and we have very low gas costs. We also plan to get a wood-fired oven with water pipes to support or replace the furnace, but we only built the chimney for this as yet.
I would go for a combined system in the long run, maybe with some solar collector support for warming up service water, and a burner that eats everything, combined with a heated water pipe system, and a well-insulated big buffer reservoir for hot water.
I know it does not help you now, but repairing old technology is mostly more expensive than thinking about a new solution that will work for 20+ years
Greetings,
Catfish