see description belowThe plumbing fixtures in my house are in two clusters - a west cluster including 3 bathrooms on two floors and two kitchen sinks (20 feet at most from hot water heater) and an east cluster including 1 bathroom and laundry room (70 feet at most from water heater). This is new house (2 years old) and since beginning of occupation we have noticed that two kitchen sinks less than 10 feet from water heater never have hot water - not like any of the bathrooms or the mop sink in laundry room (70 feet away). I crawled under house and discovered that kitchen sinks are last in hot water system travelling over 100 feet. The hot water line continues past kitchen sinks and back towards water heater. It appears to be stubbed just 5 feet below the hot water supply line (see photo hot water supply top of photo, stub near bottom of photo). Under the floor, the two lines are just a few inches apart. If I connect the two lines, will it improve hot water to kitchen. What are potential issues with such a connection? Should I do the connection in crawl space or next to water heater?


1 Answer 1


Pure guess, but:

It sounds like someone might indeed have considered setting up a hot water return loop. Done right this can continuously replace the water in the pipes with fresh hot water, so you always have hot water at the tap almost immediately. (Well, modulo someone emptying the hot water tank with a long shower.)

However, that approach can also mean a lot of energy goes into heating water that just cools off before being heated again.

It's more often used in large buildings where nobody wants to wait at 3AM for hot water to come up from 37 floors below. I have seen mention of residential versions but I have no idea what the details or operating costs would be.

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    Having had one in my previous house, the costs are high. I ended up ripping out the floor on the second floor and short circuiting them. Jan 21 at 3:32

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