I have a pre EPA FireChief wood furnace. It came with the farm house when we bought the farm. It works well and is in decent shape. My concern is the clay tile lined cinder block chimney. It can get fairly warm during a continuous burn. It's not too hot to touch, and I've taken infrared images of the chimney and no hot spots were found. I sweep the chimney twice a year. This year I attached my cell phone and some led head lamps to the sweep rods then lowered it down the chimney for an inspection. I live streamed the images to my son's phone so we had a live feed of the inspection. There are a few cracks but I didn't see break through or shifted tiles. The chimney is 50ish years old so I want to do a solid liner install before it's needed. Current setup is 3 ft of 6" split seam single wall from stove to chimney. At Chimney there is a 6" to 8" adapter. Chimney wall has an 8" thimble into a 8"x8"ish, I think it measures a bit larger inside, clay tile up to the roof. It's at least 25' to top of chimney crown. I don't have exact numbers because the chimney is being used 100% right now. Looking for install tips and recommendations to a supplier/product. There are no local chimney sweeps or installers. I want a rigid stainless steel liner. I can and do burn some coal so it looks like 316 stainless. I've seen some rigid liners, in the past, had an optional insulation wrap. Could I run 6" liner with 1 inch insulation or 8" liner with no insulation, or just 6" liner no insulation?
If the furnace is 6", go with 6" liner with 1/2" insulation wrap. Why rigid? I'm told a quality flex liner can go 30 years.
Mostly personal preference. Solid welded, smooth wall pipe will always flow better and be structurally stronger than a 2 layer flex with smooth interior. I'm not seeing much of a price difference and my chimney is a straight shot up and down. Chimney is inside the house and not exterior of the house. I have one buddy who had his house burn down after a flexible liner was installed by a local installer that is no longer in business. I never saw the liner or heard the root cause of the failure. I assume the inner layer had a kink, or defect where the metal wrap opened up. Maybe a poor 90 install.
Yeah that doublewall smooth inner is to be avoided, it's actually inferior to single wall flex liner. It doesn't flow any better, and commonly has structural issues and then traps creosote...sometimes the simplest mouse trap is the best one. Sounds like rigid is a no brainer then...just use insulated.
