Well done, Reuben. I don't know if you encounter this in your area, but here there are homes built before the '60s or so with old transite (cementitious/asbestos) flues, where someone has replaced the water heater and improperly "attached", or stuck, the metal connector into it. This creates the same problem as the orphaned water heater, condensation and rusted connector or even rusted water heater. Perhaps you could talk about this some time.
Excellent presentation. Thank you for this very informative video. I learned a lot! Is it safe to turn down the water temp to very low, 80 degrees or less and inspect the vent connector for blockage? My traditional, single wall vent connector, becomes extremely hot while my natural draft, “orphan” water heater is running. The horizontal run is about 5’ with a slight pitch, with one rigid metal 45 degree turn in the middle of run. There are melted seals - evidence of backdraft on the top of water tank. Perhaps the vent connector is blocked or the very cold, dense air in chimney causes the exhaust gases to build up in vent connector and backdraft?
