two appliances one flue, or heat with an old cook stove?

[offgridsomewhere]

Here is the situation that I’m faced with: I have an interior chimney that previously had a wood circulator (Suburban Woodmaster) and a wood cook stove (Knox Mealmaster) connected to it on opposite sides. Both appliances are on the ground floor, and the thimble for the circulator is about a foot or two lower in the chimney than the one for the cook stove. The old liner was 8x8 masonry, but badly cracked and has since been broken off to make room for a 6” stainless steel liner. Now, the plan is to eventually replace the cook stove with a modern one (like a Heco) that is better suited to both space heating and cooking and then remove the circulator entirely, leaving the new flue with just the cook stove. However, that’s not going to happen immediately. So, given this situation, I am wondering which is the least bad option in the interim: set up the chimney for just the old cook stove, remove the circulator, and have just the old cook stove for heat and cooking, or have both the circulator and the old cook stove attached to the same flue temporarily and only ever have one running at once.

Now, I know it’s a code violation to have two appliances connected to the same flue, and presumably a 6” flue couldn’t be big enough to accommodate multiple appliances anyway. That said, is it possible to have these two appliances connected to the same flue and it be safe (if not code-compliant) for the moment if I only ever run one at a time? On the other hand, if it just isn't an option to have both connected at once, how miserable can I expect to be with just an older cook stove for heat? (for reference, the house is a 1200 square foot central passage style, with the chimney located in the center of the rooms on the right side of the central hall)

 

[EbS-P]

Hooking up two appliances to a single flue just isn’t safe. That’s why code forbids it. For hooking up a single appliance why would you choose the cookstove over the circulator?

When lighting fires inside you house always follow code.

 

[offgridsomewhere]

Well, I guess that was part of my question: does the code forbid it because running two appliances at once is unsafe and its just heading that possibility off at the pass, or does the code forbid it because having two connected at all is in and of itself too dangerous.

As for choosing the cook stove over the circulator, because it can cook and presumably throw (some) heat, unlike the circulator. Without the cook stove there would be no means of cooking indoors.

 

[begreen]

NFPA 211 (Section 9.8) prohibits the interconnection of solid fuel-burning appliances into any chimney serving another appliance.
It's unsafe. Doing so can lead to a diluted draft and a dirty chimney.

 

[peakbagger]

Space Bus (a hearth member) may want to weigh in, he got a modern wood cookstove and if I remember correctly he is using it for heating quite effectively. I bought a wood boiler out of house last year. I think it was a single 8" tile flue that had an oil boiler and big wood boiler and I think a third wood stove all on the same flue. It was a drafty converted summer place so I do not think draft was an issue.

Note I think the State of Maine has an exception for existing homes with only one flue can have an oil boiler and wood boiler on the same flue. It was very controversial when it passes as Maine is usually a stickler on legal boiler installs.

 

[offgridsomewhere]

Space Bus (a hearth member) may want to weigh in, he got a modern wood cookstove and if I remember correctly he is using it for heating quite effectively. I bought a wood boiler out of house last year. I think it was a single 8" tile flue that had an oil boiler and big wood boiler and I think a third wood stove all on the same flue. It was a drafty converted summer place so I do not think draft was an issue.

Note I think the State of Maine has an exception for existing homes with only one flue can have an oil boiler and wood boiler on the same flue. It was very controversial when it passes as Maine is usually a stickler on legal boiler installs.

Interesting. This house probably used to be coal-heated. Each set of rooms on either side of the central hall has an interior chimney with the chimney situated between a partition (as in, two bedrooms share one chimney, the living room and kitchen share one chimney). There's a disconnected top loading coal stove in each of the bedrooms, so I'm guessing the living room/kitchen chimney also had coal appliances connected previously and that they were at some point replaced with wood burning ones. There is what appears to be smoke damage on the walls in the kitchen, so the switch was probably not wholly successful.

 

[EbS-P]

I brought up the UL label because if it doesn’t have one even using proper shielding you can only reduce clearance to 11” (I think but don’t hold me to it). And your insurance company might not like an unlisted stove and especially one that doesn’t meet clearances.

 

[electrathon]

Safe is a very relative term. It would likely work just fine. But if something worked just fine for 999 people and 1 person burned his house down, it would be considered very unsafe. There are a lot of places in in this world that have common chimneys. It almost always works. Almost always isn't good enough to be considered safe. You need to move into the virtually always range to be acceptable.