5

I bought a tankless water heater that allows me to vent using category III. I've seen that wall thimbles are included in many category III termination kits, but am wondering if they are really necessary as the flue doesn't seem to get very hot.

  • Are wall thimbles necessary for side venting category III flue though combustible materials like plywood??

  • How about for category IV?

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.