Draft Hood Venting

[syq4ever]

Hi everyone! I've searched online for many hours and was not able to get the answer that I'm looking for. I would appreciate any help from this forum.

Basically the previous owner installed the water heater without a drip pan, aluminum flexible vent pipe that often used on dry clothe machine, and no discharge pipe (which I hired a plumber and took care of it last week for $120). So I'm basically down with two code violations I think. An inspector is coming to check my recent home electrical upgrade next week, I'm afraid that he might gives me a hard time or fail me on the water heater installation because when he goes to check the new electrical work that was done to the WH as part of the work, he might points out the violations. For that reason, I would like to take care any problem now so that I can pass the electrical inspection without any other problems.

So here is the question and I'm going to ingore the drip pan at this point because obviously it's too late to install it (the plumber quoted me $500 to install the damn thing). 1) For the aluminum vent pipe that was already installed, is it acceptable? I've searched and some online source says it's not but not sure if this apply to CA. For the east of mind, I've bought new materials last night and thinking of changing out the pipe. What I bought was:
- several galvanize 90 degree elbow connectors (due to limited of vertical space)
- a 3' galvanize steel pipe that will connect to the elbows and the ceiling.
These are measure at 3" BTW which I believe what my 38 gals WH is. 2) Is it allowed to use 90 degree elbows for the venting? 3) From my understanding, the clearance from the draft hood to the first bend of the vent pipe has to be 1' but mine is going to be 1/2', is this ok?

Thanks!

 

[syq4ever]

So I went ahead and replaced the venting pipe from flexible aluminum to the galvanize steel 90 degree elbow connectors that I've purchased. One thing I've noticed this morning, does the galvanize vent pipe suppose to be kind of warm? Is it the combustion gas that pass through the draft hood into the vent pipe that cause it to be warm? The flexible aluminum pipe didn't have that problem.

This morning it also had a little rubbery smell. I think this might have came from the new product because it was a little greassy from the store (Lowes). Does anyone think it was the grease that got dried up and caused that smell or something else?

Thanks.

 

[havasu]

Is this vent pipe double walled? What you are describing sounds to me as if it is single walled pipe. If so, this is illegal and dangerous because of potential fire hazards. I hate to say this, but I believe it is time to spend a few bucks and get an expert in there to keep you and your family safe, not to mention it would never pass an inspector.

 

[syq4ever]

Yes I believe it is a single wall pipe. Is there such thing as double walled? I was at Home Depot and Lowes looking at the product to replace, and I did not see any venting pipe that was double walled. BTW, my sister in law who lives down the street, her WH was also appear to be a single wall or layer of steel because I purchased the same material of planning to use it which I ended up didn't use it.

Could you also answer my question, is it normal for the vent pipe to be a little warm? Please continue to guide me through this and if I need to hire a plumber, I will do so.

Thanks,

 

[havasu]

Your pipe usually needs to be double walled and there are many codes regarding 90 degree elbows, which are usually prohibited. Also, I know the codes have changed in recent times, and if installed at floor level (inside), you must have a drip pan to catch any water in the event of a leak. If installed in a garage, I believe the W/H must still be installed 18" from the ground to prevent explosions from gas fumes.

What I am trying to say is this is something that you need to be completely accurate with installation, because of the many dangers.

 

[syq4ever]

Havasu,

So is it this a code violation only in CA?

BTW, even though the connectors that I used and joined together to make a vent pipe from the draft hood to the ceiling, the elbows are tilted 45 degrees up until reached the ceiling. Could you please explain to me what potential hazard this can cause?

I also found more info about the single wall vent pipe use from this website:

Single wall gas water heater vent pipe cannot be installed closer than 6″ from any combustible materials such as floor / wall framing, paper, etc.). Such installation could create pyrophoric conditions and a fire-hazard.
Pyrophoric condition is when a material ignites spontaneously at significantly lower temperature if it is constantly exposed to heat. So, if something would normally ignite at 500F, by applying constant heat to it, that ignition point might be lowered to let’s say 250F – it’s just an example…

■Single wall natural draft gas water heater installation vent pipes cannot be used in unheated areas like attic or garage (even if only partially penetrating that space) , because such vent pipe installation will cause excessive condensation on vent pipe walls and compromise proper drafting – double wall pipe / B-vent type is required.
■Single wall natural draft gas water heater vent pipe can not be used inside the walls, ceilings and any inaccessible areas – double wall type vent pipe / B-vent must be installed.

My WH is in the laundryroom and is more than 6" away from the painted interior wall and is raised 18" over the floor. Is it still unsafe?

 

[lma1]

I think guessing what kind of vent that is suitable or permissible for your HW tank is at best dangerous without knowing what kind of heater you got. They’re many kinds of vent (double-walled B vent; Type BH, BW & L; single-walled C vent; chimney; direct vent and so on) that are used with domestic HW tanks & boilers.

You might want to share the nameplate information with us or look up the installation and operational manual to find out what vent is listed and approved for use with the particular type of heater you got. If you don't have one, get one from the Manufacturer or its representative.

 

[syq4ever]

I currrently have a Rheem 38-gal WH and this is all I can remember on top of my head. Also, the connectors that I am currently using are single wall galvanize steel.

I got this info from Rheem website for both 40-gal and 50-gal.
The water heater must be vented to the
outdoors as described in these instructions. DO NOT connect this water heater to
an existing vent or chimney - it must
be vented separately from all other
appliances.
NOTICE: This unit can be vented using
only the following recommended pipe
material. Use only 2- or 3-inch diameter
pipe. PVC (Schedule 40, ASTM D1785)
CPVC (Schedule 40, ASTM F441)
ABS (Schedule 40, ASTM D2661)
ABS (Schedule 40 DWV, Cellular Core,
ASTM F628)
The fittings, other than the TERMINATION,
should be equivalent to the following:
PVC (Schedule 40 DWV, ASTM D2665)
CPVC (Schedule 40, ASTM F438)
ABS (Schedule 40 DWV, ASTM D2661)

I just read this from another online resource in South CA: Where it passes through walls or roofs, a vent should be double-walled. And the single-wall vent sections, which are crimped and shove together, should be screwed with three screws per section, especially in earthquake country.

My pipe isn't running through any walls. It is about 2 feets below the ceiling in the laundry room and all the connectors makes a 45 degrees from the draft hood to the ceiling cap where it then vent outside the house. I did used metal screws at each connection joints.

Thanks for the help so far.

 

[havasu]

You should be good using the single wall pipe then. I still think you will get dinged for not having a W/H drip pan though. If not, it still would be a good idea to install one asap. Your insurance may not pay off if you have a leak which causes damage.

 

[Otahyoni]

Mark, my water heater is set up similar to his. No drip pan, and single wall vent pipe leading into a chimney. It was installed by a plumber so i assume its right...

Now if i can get those damn cats to stop knocking the hood off the heater so its vented to the chimney instead of into the basement....no wonder i always have a headache.....

 

[havasu]

Every city has their own codes they are sticklers with. From what I understand, if the W/H is in a living space on the same flood plain as the interior flooring, then code dictates it must be in a drain pan. If the W/H is not in a living space (ie garage, shed, outside, etc.) then this rule does not apply. In the latter, the W/H must be elevated 18" to prevent flammable fumes from igniting a fire.

Regarding single or double vent pipes, syq4ever is spot on IIRC. The problem with posting on a forum, in a different region, and with no pictures, causes many to assume the worse, not knowing if the vent is isolated from wood studs, single or double wall. Most people replying here will always guide you with the safest installation and it may not always be necessary, but will be safer for the poster's family.

Lastly, codes change often. Something that was installed 5 years ago might have been allowed then, but will be prohibited today if new construction is completed.

 

[syq4ever]

Thanks Havasu for you continuing help with this subject. I will remember to post pictures next time to better explain my situation. My inspection is coming up very soon, so I'll let everyone knows how it went.

- S

 

[havasu]

Please do!

 

[syq4ever]

I passed the inspection!! Thanks everyone, particular havasu for your help on this subject. The inspector came, looked at the electrical work and commented it was a clean job, then looked at the WH briefly and passed us. It sure feels great for not having to deal with the WH anymore.

Cheers!

~ S

 

[havasu]

Comments like that coming from an inspector is something to be proud of. Congrats and we'll be here next time you need us. Also, there is other good stuff within this forum if you'd like to stick around!

 

[syq4ever]

Thanks Havasu! I'll be sticking around for a long long time! Reason being is because my home still have other minor plumbing issues (hammering water noises, water pipe making noises after being shut off, etc.,) that I will look into in the near future. Our home was built in the 50's so I'm sure there will always be plumbing issues that will make me seeking for help again.

~ S