Last winter the condensation from our high efficiency furnace caused our line to freeze from the floor drain where the water was running into, all the way to the septic. No one was there to flush toilets or run water more than the drips that comes from the furnace. It was below 0 for several days prior to that.
Where do you suggest we run the water from the furnace instead of the floor drain?
The furnace is in the basement and not near an outside wall.