gas water heater venting questions (need it out of my chimmey!)

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Feb 1, 2012
89
Southern NJ
Greetings, I'm hoping someone with a little knowledge of gas appliances can steer me in the right direction. I've currently got my hot water heater vented into my chimney and want to get it out so I can run a woodstove through the chimney.

Is it safe to run the exhaust up INSIDE my drywall, through the plate and out the ceiling? Id much rather redo some drywall than run the pipe up the outside of the house.

If its safe how should I insulate? I'm thinking of boxing it in with metal stud and using sprayfoam.

Last question, how far can I run the exhaust horizontally before havving to turn it up through the plate without affecting its function? I really appreciate the help and hopefully once this is done I can get on with installing my damn woodstove.
 
I would get a new one that is direct vent or power vented through the side wall. I have an American DV that was given as a promo from my propane supplier that has worked flawlessly for over 15 years.

Ehouse
 
I've looked at direct vented heaters and it would seem it would be more cost effefctive for me to vent the current one (1yr old, it was there when I bought the house) differently. Appreciate the fast response though and hopefully someone can chime in.
 
I am no expert but each manufacturer probably has specific requirements for venting. What type brand and model is it? Find the owners manual and I am sure it will answer your questions. If you can not find it I am sure it can be found online.
 
If it is not a direct vent product then it must be vented using class B flue if not running through the existing chimney. That means you will have to find a way to run the 4- 5" od class b flue up and out paying attention to code clearance requirements to surrounding enclosure. So you could move the water heater to an outside wall pass thru wall and build an out side chase to run vent pipe up. By the time you do all that it would be cheaper to just get the direct vent unit as it is most likely that there will not be any walls with sufficient room internally to accomplish your proposal. You also could position the heater so as to be able to run the vent pipe up a corner of a room and simply add a panel to that corner making a triangle of internal space for the flue still really not cost effective. It is also likely that you will need to line your present chimney to make it code compliant for the solid fuel device. Which opens another can of worms as your present chimney may not be large enough internally to accomplish this without removing the clay flue tiles. Most stoves require a 6"id flue, an insulated liner for a 6" id flue is going to be 8-10" od. Most home chimneys from the 50's on will accept a 5" liner with out a problem. This may or may not provide enough draft for a solid flue device. Your local codes will also have a play in this as well as your insurance company ( they are the ones you have to watch out for). So first things first , talk to your insurance company, then your local govt. troublemakers before you do anything.
 
therdlesstravld said:
...I've currently got my hot water heater vented into my chimney and want to get it out so I can run a woodstove through the chimney....
If your chimney is large enough, consider researching a liner for your wood stove and a liner for your water heater side by side.
 
jimbom said:
therdlesstravld said:
...I've currently got my hot water heater vented into my chimney and want to get it out so I can run a woodstove through the chimney....
If your chimney is large enough, consider researching a liner for your wood stove and a liner for your water heater side by side.

I don't think you'll find an inspector to sign off
on that idea. One appliance per chimney flue
is the rule of thumb, & parts of NFPA 211 specify
that. There are exceptions, but the guy with the
Red Pen (AHJ) has the final say so...
 
Thanks for all the replies I can barely keep up with you guys at work. I realize a direct vent systen would be my easiest option but seeing as the heater is only a year old id like to try to keep it. Taking the exhaust through the foundation and up the outside of the house through a chase is an option but id really rather have it inside so the wife doesn't complain about how it looks (not my top consideration but what can I do). I've got a header support beam I could box something out right up to for an inside chase and as a carpenter I wouldn't need to pay anyone to do it so I could save a few bucks.

Where can I find information on the size of the chase and how it needs to be built to be code compliant? With the 2" exhaust how large would I needd to make the surrounding? I really appreciate everyones help but would like to look into going this route before looking at other options.

P.S.- running the stove through the chimney is a whole other monster but I'm planning on running chimney pipe all the way down the chimney to avoid having to reline it.
 
Call your local code enforcement office and speak with the fire inspector and probably the building inspector as well. They will answer the questions you have about code compliance. The pipe I provided a link to says it requires a one inch clearance to combustibles.
 
Ill check oout the link to the pipe and give the fire inspectors office a call after work thanks a lot. I'm just trying to make. Sure running the vent through the house is safe and doable and not a pipe dream of mine. Do people have inside chases often?
 
therdlesstravld said:
Ill check oout the link to the pipe and give the fire inspectors office a call after work thanks a lot. I'm just trying to make. Sure running the vent through the house is safe and doable and not a pipe dream of mine. Do people have inside chases often?

For my wood stove I have an inside chase that my class a pipe runs through in an upstairs bedroom. In my opinion it is safe as long as you have the right clearances and your pipe is braced properly so it does not move. Good luck.
 
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