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04-27-2011, 08:13 AM #1
Water heater vents via flex-pipe through ceiling.
In a 25 year old home in Nevada, a direct vent gas water heater has flex-pipe connected properly going though sheetrock ceiling properly and is connected to the b-vent (mounted properly) about 8" into the attic. All is installed correctly away from flammable materials and with correct hardware. Question is... can the flex-pipe be used through the ceiling or does it need to connect to the b-vent before the ceiling.
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04-27-2011, 11:01 AM #2
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04-27-2011, 11:39 AM #3
Re: Water heater vents via flex-pipe through ceiling.
I have to agree with H.G. The information provided is confusing and doesn't seem proper at all. Direct vent usually means venting through the side wall or directly out of the roof. Is there a listed flexible vent connector? The only listed flex pipe I am aware of is listed to be used as a chimney liner. If there is then the penetrations, clearances and connections are governed by the manufacturer's listed instructions. I would really like to see pictures of this. It sounds like one of those D-I-Y homeowner projects to me.
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04-27-2011, 01:28 PM #4
Re: Water heater vents via flex-pipe through ceiling.
Seems pretty straight foward. The answer is no. The vent connector can not extend above the ceiling, they can't be in a concealed space.
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04-27-2011, 01:39 PM #5
Re: Water heater vents via flex-pipe through ceiling.
In the mean time I contacted a local code inspector. He understood the issue and Mathew was correct. You cannot connect a flex-pipe to the b-vent in a concealed area. It must be connected within the room in which the water heater stands.
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04-27-2011, 01:53 PM #6
Re: Water heater vents via flex-pipe through ceiling.
I think I learned something here. But is that flex pipe an approved connector? I thought that had to be single wall hard pipe to the B-vent connection.
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04-27-2011, 02:05 PM #7
Re: Water heater vents via flex-pipe through ceiling.
I am a little confused! Where does this "direct vent water heater" get its combustion air? If it is indeed a direct vent gas water heater I believe it should have a stainless steel double walled flue.
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04-27-2011, 02:10 PM #8
Re: Water heater vents via flex-pipe through ceiling.
That's what I thought too, but I looked it up and there are Water Heaters that are considered direct vent similar to a direct vent fireplace. They vent right out the sidewall of the house. Combustion air is obtained like normal water heater installations.
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04-27-2011, 02:25 PM #9
Re: Water heater vents via flex-pipe through ceiling.
I am heading to that house now. I will post pictures of the actual set up shortly. For now.. this generic picture shows basically what I was talking about except for the difference that the flex-to-b-vent connection in this house is in the attic. The flex-pipe goes through the opening rather than being connected prior to the opening.
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04-27-2011, 03:16 PM #10
Re: Water heater vents via flex-pipe through ceiling.
They make flexible B-vent pipe, I see it often. You need to look at the connectors at each end for the markings that say it is double wall B-vent.
This site has some information on it http://www.mtlfab.com/media/L1940.pdf
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04-27-2011, 05:14 PM #11
Re: Water heater vents via flex-pipe through ceiling.
That says this: "Use B-Flex™ anywhere B-Vent is required, except where pipe penetrates the structure; walls, floors, ceilings, roof.", which means the answer is still 'no', even flexible B vent is not allowed to penetrate through the ceiling, walls, etc.
Not implying that you said it would be okay, just clarifying that it would not be okay as you did not state that.
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04-27-2011, 05:42 PM #12
Re: Water heater vents via flex-pipe through ceiling.
Show me a "direct vent" "Water Heater" that is LISTED to use Type B Gas Vent in a vertical orientation while functioning as and remains direct vented, and is listed to use B-vent while still functioning as a "direct vent" appliance, and I'll buy you lunch. (I've got one gift card here in an envelope with stamp ready to be addressed, and I'm happy to buy your lunch to learn about some new development.)
Direct Vent Appliances. Appliances that are constructed and installed so that all air for combustion is derived directly from the outdoors and all the flue gases are discharged to the outdoors.
Categoy I Vented Appliance. An appliance that operates with a nonpositive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.
Special-Type Gas Vent is NOT Type B Gas Venting, neither is Type L.
Special-Type Gas Vent. Gas vents for venting listed Category II, III, and IV appliances.
Type B Gas Vent. A vent for venting listed appliances with drat hoods and other Category I appliances listed for use with Type B gas vents.
Type B-W Gas Vent. A vent for venting listed wall furnaces.
Type L Gas Vent. A vent for venting appliaces listed for use with Type L vents and appliaces listed for use with Type B gas vents.
All listed venting systems are required to be installed according to their listing and manufacturers' instructions. This includes proper supports, stops, thimbles, terminations, clearances, and proper penetrations. You'll find that all such listed system componants are initially marked or labeled with identifications.
Last edited by H.G. Watson, Sr.; 04-27-2011 at 06:01 PM.
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04-28-2011, 06:08 AM #13
Re: Water heater vents via flex-pipe through ceiling.
The OP said "direct vent". I am guessing this is actually a power vented unit, in which case, you cannot use B-vent or any of its flexible derivatives to vent it. It must be either venting listed for use with positive vent pressure or the plastic venting specified by the mfr---period.
OP: can you post make and model of the WH? Maybe a pic or two? Otherwise, we're all punching sand here.
Keep the fire in the fireplace.
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04-28-2011, 08:30 AM #14
Re: Water heater vents via flex-pipe through ceiling.
This is the actual set up. You can see it is not a power vent water heater.
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04-28-2011, 09:03 AM #15
Re: Water heater vents via flex-pipe through ceiling.
Ok, from here it looks more like a natural vent gas WH without a draft hood connector with inadequate vent rise, lack of proper firestopping, and an improper connection to the vent or whatever is up inside that pipe. You also probably have a clearance issue to that pvc pipe. This appears to be an alcove installation, which could also be a problem. Also calculate MUA. While listed flexible B-vent connectors are very stiff and tend to hold their shape, they still should have support, which this one does not. This appears to be a 4" connector-what size is the draft hood take-off? At this severe offset with no appreciable rise, the 4" may be insufficient for even a 40mbh unit. Check the venting tables.
Looks like you don't have a 1" clearance where the flex meets the ceiling.
If that is the TPR drain, it should be copper or CPVC--not PVC and is not routed properly.
Do you have a pic as viewed from above?
Keep the fire in the fireplace.
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04-28-2011, 10:10 AM #16
Re: Water heater vents via flex-pipe through ceiling.
Bob,
BW makes DV WHs.
residential BWs specify/use proprietary venting/attachment kits AFAIK.
To me this almost looks like a DS model which has been stripped and modified missing plenum box, etc. Such as a DS1- (40 or 50) S6.
3"/5".
No matter which model, type, etc. it is wrong, that's for darn sure.
Want model number and info from OP. If there is no data "plate"/label then its additionally wrong and dangerous.
BTW that first photo "vent connector example" has a flex connector which is "identified" or "labeled" "3FC3" that's an identifyable part number from Ameri.
To the original poster,
The opening in the ceiling apparently up to the attic might have been for make-up for an enclosed space residential, not a space to fill/send a gas vent. Almost wonder if the original WH was electric and there might be a clothes drier in the same enclosed space or alcove. IIRC that's 1 sq. in. /4,000 BTU for each (x2) vertical opening for outside air enclosed spaces.
These "houses" wouldn't just happen to be mobile homes or manufactured homes would they? Looks like what's already (oversized opening) in the ceiling might be a MH "roof jack" kit - is it?
Last edited by H.G. Watson, Sr.; 04-28-2011 at 11:24 AM.
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