Thread: Water Heater Vent

OK, sure sign of getting older. I inspected a house today and the water heater had a 3" vent pipe. Something in the back of my mind is yelling at me that it should be 4 ". Sorry no pics (the one I took did not come out). It runs up an interior wall from the basement and through the roof. It is venting all by itself.
Thanks

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Lee,

IRC 2003 M1803.3.3 Size. A connector shall not be smaller than the flue collar of the appliance.

Exception: Where installed in accordance with the manufacturers installation instructions.

You might want to check the Manufactures Install Instructions to see if 3" vent is allowed.

Thanks Billy,
You answered my question, the pipe is the same size as the flue collar and is not reduced.

Hello
I am about to install a standard (home depot) gas water heater in my basement along one of the exterior walls ( I am in northern california). My intention was to vent it directly through the wall with the vent being sloped upward maybe 30 degree, the maximum length of which may be 24-36". I am aware that by code and manufacturer's recommendations, vertical venting through the roof is specified but I wonder what are the practical issues of venting as I want to do, through the wall. As I plan a major remodel, ultimately, I will vent it properly, through the roof, but as for now, would the water heater vent properly through the wall?
Thanks

Originally Posted by lim ace

I am aware that by code and manufacturer's recommendations, vertical venting through the roof is specified but I wonder what are the practical issues of venting as I want to do, through the wall.

Death.

Life insurance hassles.

Next of kin having to be the executor of the estate.

Probate.

Really no problems at all, I guess, not when one considers how easy it is to do it wrong.

Standard vent water heaters up to 45,000 btu's can be vented with 3". So its always wise to look at the BTU of the heater.I forget what the max Btu's is for 4", 99% of the heaters I install are no higher than 45K. The ones that are higher are usually power vented. When I do get the call for the 50K - 75K BTU heaters they all are 4".

Originally Posted by lim ace

Hello
I am about to install a standard (home depot) gas water heater in my basement along one of the exterior walls ( I am in northern california). My intention was to vent it directly through the wall with the vent being sloped upward maybe 30 degree, the maximum length of which may be 24-36". I am aware that by code and manufacturer's recommendations, vertical venting through the roof is specified but I wonder what are the practical issues of venting as I want to do, through the wall. As I plan a major remodel, ultimately, I will vent it properly, through the roof, but as for now, would the water heater vent properly through the wall?
Thanks

One thing I always been taught in my 40 years of life, is if you are not going to do it right (in your case to code or manufacture installation instructions) do not do it at all.

Originally Posted by lim ace

Hello
I am about to install a standard (home depot) gas water heater in my basement along one of the exterior walls ( I am in northern california). My intention was to vent it directly through the wall with the vent being sloped upward maybe 30 degree, the maximum length of which may be 24-36". I am aware that by code and manufacturer's recommendations, vertical venting through the roof is specified but I wonder what are the practical issues of venting as I want to do, through the wall. As I plan a major remodel, ultimately, I will vent it properly, through the roof, but as for now, would the water heater vent properly through the wall?
Thanks

Welcome to the board..... this probably the last place you want to ask how to half-arse something.... We all lean towards being perfectionists.... some might even say to a fault

The chances are greatly in your favor that it would be fine.... BUT, if it's not the consequences pretty much suck (See JP's post above).

Thanks guys for the prompt replies and warning. As a licensed contractor and unlicensed (as of yet) architect, my MO is not to fight the rules but to understand the why of things so I can better follow them or come up with a better alternative, albeit a temporary one. In my field (s) to be creative might open me up to potential litigation and death, but how great the rewards to stumble upon a solution that everyone else said to be impossible!
Does it make any difference if the wall where the water heater vents does not have any other opening where exhausts and fumes may enter? The water heater would be installed per manufacturer's and code recommendations but for the venting, which I would change to the proper one as soon as I get to that area of the remodel (matter of months I hope). For the knowledgeable among you, please explain to me the why behind the issue?

Lim,

Why don't you take back the HD water heater, and pick up a direct vent model?

I guess I could, but I have already opened this one out of the box, have paid $100 cheaper than normal price (wrongly priced item), I have heard that direct vented models cost a great deal more, and finally in a couple of months, this won't be an issue as I could get to that area of the remodel where installing a through-roof vent won't be a problem. Furthermore, we have visitors coming in this week for 3 weeks and the small electrical water heater we have servicing the bathrooms is not sufficient for the needs of 8 people and I don't wanted to get involved in returning this one and shopping for another right now. in the worst case scenario however , I'll vent it through the roof, even if i have to reroute the vent in a couple of months.

Thanks for the help. I am planning on cutting a couple of holes into the adjacent wall and covering them with wire.

Originally Posted by lim ace

The water heater would be installed per manufacturer's and code recommendations but for the venting, which I would change to the proper one ...

I am now confused ... thoroughly so.

You say:
a) "The water heater would be installed per manufacturer's and code recommendations ... "
then switch to:
b) "but for the venting, which I would change to the proper one ... "

Either it is a) or it is not, and if b) is part of your equation, then it definitely is NOT a) as a) INCLUDES proper venting.

For your described water heater, gravity natural drafting, there is a minimum vertical height of the vent above the draft hood of 5 feet and maximum horizontal offset (which depends on the installation and the manufacturer of the vent) which is AT MOST 100% of the vertical height, but may be as little as 75% of the vertical height.

Thus, at most, the horizontal offset will be 5 feet with the minimum required vertical rise of 5 feet, and that horizontal offset may be limited to 3 feet 8 inches. AND the minimum vertical rise before any horizontal offset is 12 inches.

For the knowledgeable among you, please explain to me the why behind the issue?

I am not the knowledgeable one here, Bob Harper may see your post and reply - he IS the knowledgeable one here on this stuff, but ...

... Those requirements are to, at the most minimum requirements, and at the most typical of conditions, help get a proper draft going up the vent.

If you do not get that proper draft going up the vent, the by-products of combustion may well back draft back to the space where the water heater is located, and the results can be quite deadly.

I am not sure that I would even consider tampering with, or experimenting with, trying to come up with a magical solution to which others have not yet found (and possibly for very good reasons they have not found it).

I see, unfortunately, many cases where architects went out of their way to create something "different" without giving the proper and necessary care and understanding as to why it was "different" and not "common" - because it does not work.

You've heard, no doubt, of Frank Lloyd Wright? Many of his buildings were maintenance nightmares due to things not working as they should have worked.

My attempt, with using the BUT was to show that all the other requirements to the installation would be respected EXCEPT for the venting.
Also i am not looking for a magical solution, I am looking for a simple, or at least rational explanation behind why venting horizontally with a slope would not work adequately. Not being a plumber and not having much experience with venting gas appliances, along with guidance, I am also looking for education. I am that kid could keeps bugging you with whys until you offer the proper if not satisfactory explanation.
Regarding Frank Lloyd Wright, I would pay to have the career he had and the architectural legacy he left, ongoing maintenance be damned. Since I am not him however, I ask for help and am counting on informed people like you Jerry to set me right. Thanks for the info. I think I'll just enclose the water heater in a exterior closet just outside of the basement wall, run the vent through the deck above and up the wall. I'll just have to run the gas line a couple of feet farther than I wanted to.
Thanks

Originally Posted by lim ace

Regarding Frank Lloyd Wright, I would pay to have the career he had and the architectural legacy he left, ongoing maintenance be damned.

"ongoing maintenance be damned"

To me, that is a very poor trade off.

I would rather remain unknown and have simply accomplished correctly whatever I have tried to accomplish.

Lim Ace if the manufacture and codes tell you not to vent out a wall with a standard atmospheric vent water heater you should not do it then. As Mr Peck states in his post, if done improperly you can get combustion gases in the building. Their needs to be a developed Lean on the vent to cause a proper draw of the combustion gasses.

If you truly want to vent it out the side wall return your current heater get either a direct vent unit or a power vent unit which are designed to vent the way you want. Here is a couple links for you in case you do not know what a direct vent or power vent water heater is.

Power vent heater = http://www.bradfordwhite.com/images/...eets/119-B.pdf

Direct Vent heater = http://www.bradfordwhite.com/images/...103-B_ICON.pdf

JP and Ron have covered much of the salient points here but a few are worth reiterating:

First of all, you would need to clarify the lateral offset and total vent height.

If it isn't properly vented then it is not installed per the mfrs listed instructions or codes. If something went wrong, your insurance company may be able to deny coverage.

You have described a vent that is well under the minimum requirement. Remember that codes themselves are min. requirements and do NOT guarantee performance. Esp. with atmospherically vented water heaters, you really need to stack the deck in your favor if you want to have a prayer of that thing venting to the outside.
The vent mfr may allow a min. vent ht of 5ft but the IRC Ch24's tables start at 6'. With a 3-4ft lateral offset, you're looking at less than 36,000 BTU input for a 3" vent connected directly to the appliance.

You would do well to use a 4" vent connector to the vent and make that vent a reasonable height such as 15'. You will not generate much draft with just a couple of vertical feet of venting. It will most likely just backdraft into the house.

Your vent termination at 36" would be probably 5-8 ft too short--see vent termination clearances.

It has to work, which I would shocked if your suggestion did--no offense intended.

FYI, Falling Waters is falling apart and is a monolithic piece of concrete crap. FLW may have a rep. as a great architect but some of his designs turned out to be functional junk. His fireplaces draw like a 3 yr old with crayons and crack.

In modern tight houses, natural draft water heaters become CO machines. Should really be power vented or true direct vent.

You cannot put a power vent on a natural vent appliance and mechanically force the flue gases out under positive flue gas pressure unless the appliance is listed for it, the listed power venter and venting are used per the listing, and it works. A power vent termination would suck the exhaust out of the house but again really should be listed for that model WH and have the stated clearances at the vent termination.

HTH,

Well said Mr. Bob Harper. I would just like to add, if the home is very tight, and they can not install the heater on the outside wall to use a true direct vent unit, I recommend the Power direct vent model, this way its getting its combustion air from outside. http://www.bradfordwhite.com/images/...eets/102-B.pdf

I do see why Bob Harper is The Knowledgeable One. Thanks for the in-depth explanation and suggestion. That is exactly what I was looking for. I could have just gone to the local HD and be told not to vent it horizontally but without any supporting rationale behind it. As I said in my last post, I will install the water heater outside the building envelope and vent it vertically.

Jerry, I forgot to put an emoticon after "ongoing maintenance be damned", I was joking. However FLW is a lot more than just Falling Waters and the few other functional junks he has designed. Let's consider the whole of his architectural oeuvre which includes constant innovation in style, substance and material. Our current awareness of nature in architecture can be traced to him, so is most design we see today, especially ones that incorporate furniture and fixtures as part of the whole. It is easy decades later to poke a hole into anyone's work and it would be difficult to find any architect, especially an innovative one who has not screwed up a few times. However a close analysis of FLW's work would make anyone give him his due, which is immense respect.