Well the furnace was not fine. The bright side of this problem happening is that we discovered that the heat exchanger had a large crack in it. The furnace was an unknown major carbon monoxide risk before this mishap. It’s 15 years old, so replacing the heat exchanger and other water damaged parts isn’t worth the money. So I get the fun of a new HVAC system after having the fun of replacing the upstairs system in 2022.
This is also a good time to replace a system as they aren’t busy.
The plumber is coming later today to look at the sump pump.