Elwood Wiles
New Member
Howdy,
I am getting ready to install a Takagi T-K4-IN tankless water heater in my basement. I've ordered and received the Category III venting pieces, including back flow preventer, 90 degree elbow, wall thimble, and terminator hood. My original plan was to mount the unit to the concrete basement wall and vent out the 2"x8" rim joist above the foundation. When I got the wall thimble, I realized the flange (10"x10") is to large to fit in that space! Now I am thinking of just venting directly through the 6" thick concrete wall, as this would also clear up some other space issues with electrical wires etc. I'm also assuming I can do without the wall thimble as concrete is non combustable
I'm wondering if anyone has vented in this manner before? I've been scouring the web looking for a precedent, and coming up short. I have several questions (if this is an appropriate method for venting)...
1.) What would be the best method for creating the 4" diameter penetration through the wall? Hammer drill with 4" diamond hole saw? Or drill several smaller holes along the circumference and chip away with a cold chisel? I'm slightly concerned about running into rebar embedded in the concrete.
2.) The horizontal part of the terminator hood (the part that goes through the wall) is exactly 6", which wouldn't leave me room to connect the 90 degree elbow, since it would be just inside the thickness of the wall... d0 1-2" long adapters exist for situations like this?
3.) Providing all of the above is possible, what is the best way to seal up around the penetration in the foundation? Some sort of high temp silicone, or?
I'm a long time follower and first time poster here at the TL forums, and any advice would be greatly appreciated! Thanks!
I am getting ready to install a Takagi T-K4-IN tankless water heater in my basement. I've ordered and received the Category III venting pieces, including back flow preventer, 90 degree elbow, wall thimble, and terminator hood. My original plan was to mount the unit to the concrete basement wall and vent out the 2"x8" rim joist above the foundation. When I got the wall thimble, I realized the flange (10"x10") is to large to fit in that space! Now I am thinking of just venting directly through the 6" thick concrete wall, as this would also clear up some other space issues with electrical wires etc. I'm also assuming I can do without the wall thimble as concrete is non combustable
I'm wondering if anyone has vented in this manner before? I've been scouring the web looking for a precedent, and coming up short. I have several questions (if this is an appropriate method for venting)...
1.) What would be the best method for creating the 4" diameter penetration through the wall? Hammer drill with 4" diamond hole saw? Or drill several smaller holes along the circumference and chip away with a cold chisel? I'm slightly concerned about running into rebar embedded in the concrete.
2.) The horizontal part of the terminator hood (the part that goes through the wall) is exactly 6", which wouldn't leave me room to connect the 90 degree elbow, since it would be just inside the thickness of the wall... d0 1-2" long adapters exist for situations like this?
3.) Providing all of the above is possible, what is the best way to seal up around the penetration in the foundation? Some sort of high temp silicone, or?
I'm a long time follower and first time poster here at the TL forums, and any advice would be greatly appreciated! Thanks!
