Search the Community
Showing results for tags '80%'.
I've certainly seen older systems with NO staining, or deposits at the flue collector gaskets. (maybe they were changed....) These were two Lennox 80% furnaces, one 44,000BTU for the basement, and one 88,00 for the main floor. Vented together with a water heater. Plenty of combustion air available in the furnace room. No other signs of problems. What could be happening? How much is too much? What consequences/worse case scenarios can be imagined?