E.E.’s primary problem was not the insurance. It’s the design flaw and negligence that allows the small glitch to evolve to the full-scale catastrophe.
Every trouble that can occur occurs. Every trouble that cannot occur occurs too.
Firstly, the furnaces may fail – it’s quite normal. I have no idea about their model but I believe they should have and so have some security automation that stopped them due to some problem (electricity?), or the fuel supply failed. The first task to design should be “The stopped furnaces should not self-destruct”. How should it be done? I see at least 2 ways: either use the glycol or find some automatic valves that dump the system in emergency to the safe place.
Then, you have two furnaces. They do not heat the same area. Instead one of them heats basement and the other one heats the second floor. There is no chance that the operating furnace can heat the failed one and prevent it’s destruction.
I believe that both furnaces have a common fuel and electricity supply (a redundant propane tank and proper UPS is too costly.) Any supply problem stops them both.
Then, I think, the house has the grid power (see below). If so, the emergency electric heaters should keep the temperature at least in critical areas at least above zero.
Then let us imagine that the worst occurred. Both furnaces failed, and pipes burst. Some hundred liters of water flew to your basement. Not a big trouble. But
Water exploded out of the second floor bathroom at an alarming rate, for most of a week.
It means that either you have either a communal water supply or local electric water pump. Since the grid power is simpler to obtain I believe that you have electricity. So either your water pump has not been duly stopped before departure or your intake valve in your basement has not been duly closed (And possibly not duly heated and having no way to dump water when the valve fails). It’s not your design flaw. It’s negligence. You believed that your furnaces are reliable and you need not close the water supply. They weren’t.
And the last. Both the automatic valves that feel leaks and insulate them and the GSM controllers that can inform owners about troubles exist and can be bought and installed. But they are your last line of defense against the trouble that should not happen. – Thor A.