I bet the air conditioner isn't!

Besides, if you could buy an electric water heater that runs when electricity is mostly free, wouldn't you replace your gas heater? I would.

This is a good point, but would that ever actually happen? Or would it just be "free" electricity at first and later the electric boiler owners find out that a gas one would've been cheaper after all.

This winter natural gas prices are supposed to rise 30%.

You're taking some level of risk regardless of which choice you make or the government makes for you.

I would consider purchasing an electric boiler if the average operating cost was significantly lower. Eventually this will make sense, but it’s not something that will happen in my neck of the woods in the next 20 years.

Here in Flanders (60% of Belgium in terms of population) that is not an option. No more pure natural gas heating allowed in new construction from 2023. Gas/heat pump hybrids can still be installed until 2025, but that's it.

It's more strict for oil based heating. Even replacing an existing system is not allowed anymore from 2022.

With fixed 24/7 electric rates, it will never happen.

Are these fixed in Europe? What about night/day meters?

Night/day meters are not granular enough.