Oil Furnace and gas water heater into same flue

[Bill Thacker]

What requirements exist for venting an oil furnace (large pipe) and gas water heater in such close proximity. The water heater exhibited some signs of backdraft (fogging). The oil furnace smelled of gases when operated. below the flues is evidence of seepage from either condensation or rain (no rain cap)

Thanks

11699

11700

[wayne soper]

First off the smaller flue should ALWAYS be on top of the larger. That is all wrong.
Also oil fired and gas fired units condensing in the same flue create an acid that is flamable and also deteriorates the clay flue liner.
That being said I see it all the time. Call it and life goes on. Eventually someone is replaceing the liner.
The problems is that the oil company dosen't recommend switching to a gas fired furnace, wonder why.
And since the oil fired water heaters are expensive. this is what you get.
You can't see up the flue liner from the cleanout because there is none.
You can't see all the way down from the top because its too far and typically thats where the deterioration is.
Did you look down the chimney?:D
That is what is called a dead head, where the flue ends at the boiler connection.
This also means any debrtris falling down the flue can catch fire or block proper venting. Thats why the water penetrated right below the vents through the wall.
Google the issue and you'll find a ton of shpeal on it.
OH yeah Barry is also considered a dead head but that's a different era.:D :D

[Bill Thacker]

Thanks,

You've confirmed my conclusions and provided additional insight as well.

What alarm level would you call it?.....so to speak

[Billy Stephens]

What alarm level would you call it?.....
.
DEFCON 1 .

DEFCON 1. :D
.

[Suzanne Clark]

Have u ever seen an ABS pipe used as exhaust pipe for oil furnace? I have. I could also smell off gases.