Tankless water heater install question

[Cj3d]

Hello everyone. I’m very happy to have found this site. I am finally starting my build. I have a question about tankless water heater installation. In all the videos I’ve seen they are framing the tankless heater with wood. Is that safe? I deleted the back window on the drivers side and I am going to install it there in case I need to rinse myself or my dog off. I will need to brace/ frame it with something. I’m just not sure what’s best. Thanks in advance.

 

[nikitis]

No. Is recommend using a sealed metal box, and maybe go as far as to paint the inside with 2000 degree ceramic paint. If a fire were to occur, since the metal box is mostly air tight or close to it, there is a good chance it'll snuff out. The ceramic paint isnt 100% fire proof but it is pretty fire proof for a good long while, long enough to snuff out from lack of oxygen.

I used this paint on a pipe I made for a propane blow torch I home made and that flame gets quite hot and the paint still holds up. There should be safety mechanisms built into some of the heaters but a lot of them are made in China so there won't be safety mechanisms in many of them so you'll need to take additional action and secure it properly. A tight metal box with holes sealed with rubber grommets and coated with ceramic paint should be as safe as you can make it.

https://www.amazon.com/Rust-Oleum-248903-Automotive-12-Ounce-Degree/dp/B003CT4AKC/ref=mp_s_a_1_1?crid=162G3FIRXKNEH&dib=eyJ2IjoiMSJ9.GSViVKbo19xB2Ou5-9E4HkAagQ_1Tl9ncS6Qk4lAFbrEgJoyihOOZCzVH3zIaMN_wDH5y0v8-92h5zljFS8qC_ogGPgNL91k_WLPfbBDXIGaOUL5YB0RZHbXhQOu-pJD0khYB0wSkcbHccO0upndJ1KNDnQmZC7pAtsRClEhWrR_TCu6AGjTy0t5EiRKKi6RkZejSHvgt_Zvm3dCBs4otw.hCXYZvzqt8jQktJKxFcGO5hX_A5GAPQ8IMAcQ1KKz1s&dib_tag=se&keywords=high+heat+ceramic+spray+paint+exhaust+flat+2+pack+black+2000+0%2F0&qid=1732449107&sprefix=ceramic+paint+2000%2Caps%2C130&sr=8-1

They make a primer too if the surface of your box is too slick. Could buy both, primer it first then coat with this. Don't use regular primer, use the equivalent high heat primer from the same brand.

 

[Albatross]

Can double-verify the point on ceramic paint.

We make wood heaters, and we use a ceramic paint for the bodies of them. What kind generally doesn't matter, as all manufacturers except for one had a thermal-handling characteristic of something like 2650°F, with some of them going up above 3000°F. And just for reference, mild steel's handling capability is less than that.