Re: Is a chimney liner needed at all?
I'm not nor have I claimed to be a expert. I am basing my opinions on personal experience and the amount of money I spent on technicians, to no avail, when we installed an 80% furnace.In doing research the problem we were having was due to a chimney with to large a flue. This caused mis-fires and on cold days the WH pilot would be blown out when the power vent on the furnace would turn on. New flue liners the proper size solved the problems. In my research I found several jurisdictions that have updated and no longer allow multiple units on one flue.
I didn't take into consideration the actual equipment that you have, so I apologize for jumping the gun.
Be sure you live your life, because you are a long time dead.-Scottish Proverb