Roof Venting

nealtw said:

I would guess in the basement there was a wood or coal burning stove or furnace, the lower hole was the chimney clean out, your aero points to a fresh air vent for fire air.??
Next floor up, 2 furnaces and that exhausts into the chimney?
Where is the water tank now?
https://www.youtube.com/watch?v=RRauuzjI-H4

Click to expand...

Thanks for the clarification and video, I did not know that the bottom opening it was clean out. Yep, the next floor has two furnaces right below chimney on the roof.

The basement is relatively small and has a low-clearance ceiling, and within the basement there is a utility room (in the past it seemed to have well pump, water conditioner, etc) which recently had an electrical water heater (probably bought in the 1995):



The nipples of the old one were corroded into submission and I given that don't even know whether or not it is in proper working order I went ahead and bought a brand new 30 gallons electrical water heater as a replacement (the kenmore on the left). So, I was basically guessing that maybe a gas water heater were there in the far away past. Could I use this chimney access for a small gas tankless water heater?

I also happened to use a wire fishing in order to find the whereabouts of this basement chimney access, and it seems that it converge to the same spot whereas the two old furnaces are (there is a cylinder or hvac duct coming from a lateral wall, this is actually coming from the basement). Thus, ultimately the basement chimney access ends up in the next floor spot whereon it then connects with the same ducts used by the furnaces and then go up to the following chimney:

There was a time that it was ok to use the chimney to vent or exhaust the gas furnace, in most places now a liner is required. The chimney could be removed and space recovered. the enclosure for the metal furnace stack could be hidden in a 12 x12 space and would likely be cheaper than fixing the chimney.