In new construction I will have a wood stove and ZC fireplace on the main level, and a wood boiler and gas/oil hot water heater in the basement. The floor plan only fits a 3 flue chimney. Can any of these share a flue? 3 of the units are wood burning. Thanks.
Can multiple appliances share a common flue?
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Eric Johnson
Mod Emeritus
That's a lot of wood-burning going on in your new house.
By code, appliances can't share a common flue. As a practical matter, that's especially true with wood-burning appliances.
You'll have to vent your hot water heater some other way, seems to me.
We have a resident expert on codes who I'm sure will clarify and expand.
By code, appliances can't share a common flue. As a practical matter, that's especially true with wood-burning appliances.
You'll have to vent your hot water heater some other way, seems to me.
We have a resident expert on codes who I'm sure will clarify and expand.
The short answer is by code you can't share flues. People who know how things work in the code world know this is because of some poor installations. In practical terms, a flue can be designed so appliances on the same level can share a flue. It is hard to do though, so don't do it. Just put in separate flues for each.
jtp10181
Minister of Fire
Get a power vented water heater and vent it horizontally out the ring.
The people at Burning Issues would love this guy! Three different wood appliances in one house, heh.
I hope the ZC wood unit you are getting is not one of those open faced energy wasters.
The people at Burning Issues would love this guy! Three different wood appliances in one house, heh.
I hope the ZC wood unit you are getting is not one of those open faced energy wasters.
first of all most of the replies are true. One flue one appliance, howerver there is an exception to the rule or code.
B draft hood gas furnace may be connected using the same 8/8 clay masonry flue in combination with a draft hood gas hot water heater, providing the watter heater vent location is up stream with the burner. This can be accomplished two ways two separate flue entrances the gas hot water heater entrance must be higher than the burner entrance to the flue .The second way it to install a y in the burner flue where the gas hot water heater enters the y connection above the main burner connection. There are no exceptions for solid fuel burning appliances. However oil fired burner and oil fired hot water heater can use the same setup as the gas appliances. The theory being the flue is heated by the larger furnace producing a positive draft which assist the smaller 3' or 4' gas flue. Also the 8/8 flue area is still larger than the two applainces flue collars.
B draft hood gas furnace may be connected using the same 8/8 clay masonry flue in combination with a draft hood gas hot water heater, providing the watter heater vent location is up stream with the burner. This can be accomplished two ways two separate flue entrances the gas hot water heater entrance must be higher than the burner entrance to the flue .The second way it to install a y in the burner flue where the gas hot water heater enters the y connection above the main burner connection. There are no exceptions for solid fuel burning appliances. However oil fired burner and oil fired hot water heater can use the same setup as the gas appliances. The theory being the flue is heated by the larger furnace producing a positive draft which assist the smaller 3' or 4' gas flue. Also the 8/8 flue area is still larger than the two applainces flue collars.
precaud
Minister of Fire
What about concentric sharing - running a liner up the flue and let the gas appliance continue to utilize the remainder? I'm seriously considering doing that with one of mine. My water heater vents into a huge 11"x11" masonry chimney and it seems to me it would be completely happy with the remainder if I ran a 6" liner up the middle.
I aught to really miss spell ever word to your response and make typos. Just to give it back for your response a few days back. According to the National Gas Code, that space cannot be used
now if you have room and can fit two completely sealed liners where both appliances use the same fuel that would be ok. there are other exceptions but I would need to know the flue collars sizes and locations of the appliances. If you used separate fuel burning appliance that space is definitely ruled out. There is also a code the requires a 4" solid masonry partition between flues
installed in a masonry chimney. That's the code, but you local gas inspector probably governs what he will accept, talk to him . Crap!! did I mis spell anything? I have to go bacck and really screw it up, to get you to read it a few times.
now if you have room and can fit two completely sealed liners where both appliances use the same fuel that would be ok. there are other exceptions but I would need to know the flue collars sizes and locations of the appliances. If you used separate fuel burning appliance that space is definitely ruled out. There is also a code the requires a 4" solid masonry partition between flues
installed in a masonry chimney. That's the code, but you local gas inspector probably governs what he will accept, talk to him . Crap!! did I mis spell anything? I have to go bacck and really screw it up, to get you to read it a few times.
precaud
Minister of Fire
elk, I think you know it was all in good fun. Besides, you deserve it once in a while... if that's the worse treatment you get on this board, I'd say you're doing just fine!elkimmeg said:
I would have guessed they'd say that. I'd bet the WH into an 11x11 doesn't meet code, either. When it's on, the exhaust is barely warm when it exits the chimney.
Makes sense. What's the issue with different fuels in this case?
WH is std. 3", on main floor. Stove would be 5" (the F602 actually draws better with a 5") and in the basement.
Yeah, "ought" and a couple others but I won't tell anyone!
Thanks for the replies all. I reworked a few things, and I can get a square four flue chimney into the plan if I slide it into the cavity on one side of the ZC. If the cultured stone face on the fireplace is partially on a masonry chimney and partailly on studs with mesh, will cracking occur? Do I have options other than a masonry chimney to vent all those applicances centrally. This chimney will probably cost around $6k for a mason to build based on a little inflation over my current home. Cultured stone and studs would run me about $600 to do myself. What is the cost of the stuff that would go inside (metalbestos??)
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