Wood boiler & oil boiler in same chimney?

In reality, there is not much of an issue.
In the real world, it is not allowed by code.

Dick Hill (the inventor of the wood gasifier boiler) lobbied for years to allow this to be legal here in Maine. He has the pedigree, the history (no issues with the concept if done properly) and the previous Fire Marshall for the state of Maine, said it was not an issue.
When the current NFPA 211(?) was approved, the state started using it and the current Fire Marshall would not allow the code to be ignored.

Dick collected data and lobbied hard to allow it in Maine, no dice.

A state legislator, John Martin, had an inspection and was advised that two devices could not fire into a single flue.
He got a law passed allowing it as a grandfathered installation.

NOT allowable as a new installation, but allowable if installed prior to 1998.

Grandfathered is different than new, but politics still trumped code.

Unfortunately, even if you lie about being grandfathered, your insurance company can shut you down if you do something illegal.

Curious.

Different places have different rules. Mine has two pipes out the back, wood & oil, and they both go into the same chimney. This was done to code when it was put in 15 years ago. The only stipulation was the oil had to go into the flue pipe over the wood. It's a 7 inch stainless flue, and handles both - even when both are running at same time. The only little thing I've noticed is when the oil cuts in, it will puff a little puff of smoke out the draft door of the wood if my chimney is due for a cleaning.

maple1 said:

Different places have different rules. Mine has two pipes out the back, wood & oil, and they both go into the same chimney. This was done to code when it was put in 15 years ago. The only stipulation was the oil had to go into the flue pipe over the wood. It's a 7 inch stainless flue, and handles both - even when both are running at same time. The only little thing I've noticed is when the oil cuts in, it will puff a little puff of smoke out the draft door of the wood if my chimney is due for a cleaning.

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Ditto for mine. No problems to date. Oil over wood, 7" flue. Currently have a NY Thermal oil boiler and a Econoburn 150 wood gasification boiler. Check your local Codes and home insurance.

Earl

maple1 said:

Different places have different rules. Mine has two pipes out the back, wood & oil, and they both go into the same chimney. This was done to code when it was put in 15 years ago. The only stipulation was the oil had to go into the flue pipe over the wood. It's a 7 inch stainless flue, and handles both - even when both are running at same time. The only little thing I've noticed is when the oil cuts in, it will puff a little puff of smoke out the draft door of the wood if my chimney is due for a cleaning.

Click to expand...

I had a wood stove connected to the same chimney below the Oil boiler. I also had a puff of smoke coming out of the wood stove loading door when the oil boiler stopped. Finally I had enough money to put in a SS chimney for the Oil Boiler bringing it up to code! Was it a real fire hazard before? No fire in the 19 years both were connected!!