It takes a few minutes for my tankless water heater to warm up, so we end up wasting a lot of water in our shower. Is there a way to avoid this? A friend mentioned a “comfort valve” or something? What is it and how does it work? Or is there another solution? Thx!
Cheapskate subdivision builders commonly build on concrete slabs anymore with no way to access plumbing.
Yeah it never goes through the attic.