My gas heat goes down if electricity fails.
But duh, I am realizing that shorting the contact won’t do anything so you’re right.
But I have a small solar generator and could probably make it work from that, because it requires very little electricity, as opposed to say, a heat pump.
I.need to replace my 50 year old furnace, modern ones don't work that way because it isn't compatible with high efficiency.
I can also purchase a propane heater from Home Depot or Lowes which can run off the same gas tanks for less than $200USD.
The propane heater from Home Depot either has the same problem or it uses electricity for the air induction system.
If your goal is to be prepared, a generator and a heat pump will last longer, it will be cheaper for you and society in the long run, it will have more utility, and we have far more gasoline stockpiled and ready for emergencies than we have natural gas.
Gas spoils & does not store for very long. Diesel & propane are both better at storage.
You can even run generators off propane, though at less power than gas. There's even dual fuel (Gas & Propane) generators you can purchase for < $300 USD. It won't power your house, but it will at least be something which can charge batteries & run small appliances. They are loud though. If you own a house, getting a proper generator is the better choice. If you need something off grid or in an apartment (running on the balcony for ventilation), a single smaller generator or 2 in parallel will work. Smaller generators also save on fuel.
At the end of the day, multiple fuel sources will probably work. Wood/coal/propane/kerosene for heat, solar/diesel/propane/gas for electricity, etc. Most grid down scenarios last less than a few days.
Being able to boil water is important as well. There are often boil alerts when there are brown outs.