# Bath redo. New piping. Hot water recirculating loop, tankless, or keep as was? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 21, 2026, 11:17pm UTC](https://boards.straightdope.com/t/bath-redo-new-piping-hot-water-recirculating-loop-tankless-or-keep-as-was/1028675 "2026-03-21T23:17:27Z")\ **Posts on this page:** 1\ **Showing post:** 8
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 22, 2026, 12:31pm UTC](https://boards.straightdope.com/t/bath-redo-new-piping-hot-water-recirculating-loop-tankless-or-keep-as-was/1028675/8 "2026-03-22T12:31:17Z")
I’ve had hot water recirc in houses in the past. Was very satisfied with the results (no water waste, no time waste, negligible operating cost). As above a timer can reduce the hours of operation. Even if you leave it active 16 hours a day, you’ve still knocked 1/3rd off the annual cost, be that large or small. You can recirculate just the one bathroom, or try to recirc the whole house. The more run(s) you recirc, the greater the heat loss. Any hot water pipes that are new or are in walls you’re opening up anyhow, or are in basement areas, can be insulated. They sell foam rubber 3’ long tubes slit lengthwise for just this purpose. I DIYed installing those on the hot water runs in the accessible parts of my basement. Little cost, little effort and as a bonus the hot water at the other end of the house was noticeably warmer. Here’s some relevant history on instant hot, recirc, and heat waste: > [@Please tell me about home hot water recirculating pumps (for instant hot water)](https://boards.straightdope.com/t/please-tell-me-about-home-hot-water-recirculating-pumps-for-instant-hot-water/978238): > > I hate having to wait for hot water especially because it wastes water in my ordinarily drought stricken area. This seems like a great solution. Is it? What are the pitfalls? If it matters, my house is on a raised foundation and the plumbing is all upgraded to copper. > [@In residential construction why aren't water pipes insulated?](https://boards.straightdope.com/t/in-residential-construction-why-arent-water-pipes-insulated/1026974): > > I don’t know what current construction standards are but my house was built in 1995–not so new, but at a time when everybody started to worry about energy efficiency. Why wasn’t consideration given to insulating the water pipes? What is the standard practice today? Hot water pipes will radiate heat in the winter, so the heat isn’t wasted but I would rather have the water hot at the tap than heating dead space in my house. In summer, radiant heat from water pipes is at war with my air conditioni… --- _[View the full topic](https://boards.straightdope.com/t/bath-redo-new-piping-hot-water-recirculating-loop-tankless-or-keep-as-was/1028675)._