First, I have an old 5’x12’ coal bin in the basement of the house yesterday with a 1/4" of coal dust on the floor and a few small piles. Is this a fire hazard?
Second, can this flex conduit from the meter be considered the GEC if the meter has a wire to the rod outside?
Third, the house had a HE furnace with half/half PVC and ABS flue. Would a glued joint between the two materials be disallowed in this flue like it is in a drain connection?
I would say yes to the coal–advise to clean it up as airborne particulates could ignite (low probability however)
I don’t think you can use the jacket of the conduit as the GEC but not 100% sure…
I would say No you can’t mix plastic vent pipes. In ontario the black pipe is no longer allowed on new HE installations past 2007–but regardless mixing plastic types is not a good idea.
Did I pass? 
Pvc and ABS should not be glued together in any application, I’ll let the code gurus comment on the other stuff, but I wouldn’t do the way it is shown.
There are transition glues (solvents) for PVC to ABS but I don’t know how you could confirm which glue was used.
From what I understand the transition glues are not allowed in plumbing connections, only mechanical splices, but I have never come across this on a HE vent so I don’t know if it applies the same. It’s amazing how something new always pops up.
I have been under the assumption that transition cement (usually a mint green in color) is allowed for all non pressure joints between PVC and ABS. So I am thinking it would be allowed on a HE exhaust.
Hope this helps,
John Taylor
812-499-3838
In my area a single transition fitting using transition cement is allowed between old and new work.
Note: Transition cement does not solvent weld the pipe together.
Up here TSSA (governing body for all fuel burning and storage ) will not allow this transition. Any service work by a licensed tech to exhaust of older units with ABS must have all removed and replaced with PVC . Not worth a license to save a few bucks and if at any time a licensed tech came in to service the furnace on seeing this they would shut off the fuel supply and refuse fuel delivery or other service untill proper repairs were done.
Correct Bruce and I have found many that failed the twist test.
