Using Two Furnaces in One Chimney.

Natural gas and oil fired appliances can share the same flue, provided the flue is of adequate size AND the gas appliance vent enters the chimney above the oil fired appliance vent. There are many thousands of homes in our area with an oil furnace or boiler and a gas water heater.

rich554 wrote:Can I skip the Baro on the Coal stove since the Oil burner has a Baro already?
Does it matter if the Baro's are at different installed heights from each other?

No, they each need their own and you should have a stack damper for the oil burner.
The height is irrelevent. I would put the baro close to the thimble if possible.

Thanks Yanche, I realize this may not work in my setup. If I fire up the coal furnace with the manometer in place will I be able to tell if the chimney is actually drafting and how would I know it's drafting enough? Is this also something I'd want to test on a Cold chimney, say turn off the Oil furnace over night and test in the morning? Is it just enough that I don't smell the furnace running?

I will be sure to have CO detectors in place.

Thanks
-Rich

coaledsweat wrote:

rich554 wrote:Can I skip the Baro on the Coal stove since the Oil burner has a Baro already?
Does it matter if the Baro's are at different installed heights from each other?

No, they each need their own and you should have a stack damper for the oil burner.
The height is irrelevent. I would put the baro close to the thimble if possible.

Is there an automatic stack damper I could install on the Oil furnace? Or would this have to be a manual job?

with that small of a house and a pocono all set up like your going to the oil furnace won't ever run till you shut off your stove so really you only have one !!!!!!!!!!! I have mine that way no problems, now just get Jerrry to build it for you!!!!!!!!!!

Thanks everyone for the replies. I think I have a good handle on this project and will be ready when the stove arrives in December! I have a couple other odd-ball questions but that's best for another thread!

-Rich

rich554 wrote:Is there an automatic stack damper I could install on the Oil furnace? Or would this have to be a manual job?

It is a damper that closes when the oil burner is off and will open when it fires, it is wired right into the burner and operates automatically. They are fairly cheap too.
It also prevents a draft from robbing the heat from your oil boiler continuously. This is something most people miss on dual boiler installs, but can save money and make everything a little safer.

I could be wrong (I actually was once ), but I don't think those automatic vent dampers are approved for oil. I see them on gas boilers but never on oil.

I think a modern oil burner has an internal damper that closes when it's off, negating the need for a flue damper. It cuts off the draft inlet air. I too have been wrong, more than once, and could be wrong here. Any oil burner techs know for sure?

My Riello burner has that feature, not sure about any others.

For that flue damper what should I be looking for?

yes, yanche, it's an option on just about any oil burner that I know of, including the most common becketts and carlins.

I'm not to fond of the dampners that shut off the smoke pipe(flue dampner) If the flapper ever gets loose and the shaft turns and the end switch senses that it rotated 90* the oil furnace could come on with the flapper in the closed position.I only seen this happen years ago once but it did make a mess.Just my .02.
DON

The good thing is that when you have a coal boiler feeding heated water to the oil boiler,, the oil boiler's damper will be closed, and stay closed the number of cycles of the damper will be near zero all winter long instead of more once an hour..

Greg L
..

I can see the benefit and the draw back to this. If I skip the flue damper on the oil furnace any other safety precautions?

BTW: I have forced hot air, and no boiler. I do have (on order) the DHW kit for the Pocono but was going to install that after I got everything tested and working properly.

-Rich