Instant Hot Water

[mcp6453]

Home Depot is hawking a system for recirculating hot water such that each faucet in the home has instant hot water. Does anyone have any comments, good or bad, about these?

[Percival P. Cassidy]

I've seen them in other "home improvement" stores too. I get the impression that they are aimed at people who want everything "right now." How long does it take for the water to run hot in a house with well-insulated hot-water pipes? And would it not work only for a building where the hot-water pipes all run in one direction from the water heater? Pipes run in both directions away from our water heater?

I can't imagine recovering the cost (through saving a little water) in less than a decade or two.

Perce

[Paul Franklin]

The original systems circulated water constantly, or least constantly during certain times of the day (set by a timer for say, morning and evening). I feel these waste energy.

I like the systems that require you to press a button when you enter the bathroom, say. Then it pumps water from the hot side to the cold side until the temp sensor senses the water is hot and it shuts off.

With that kind of system, you don't waste water, and only a minimal amount of electricity is used. You can choose to press the button or not based on what you will be doing in the room.

Very convienent. Saves water but doesn't waste energy.

My $.02

Paul F.

[Steve Barker]

I can tell you, mine takes 30 seconds and a full half gallon to get hot at the kitchen. Not only a waste, but also an extra load on the septic. It's not about recovering the cost, it's about having hot water without waiting. When you only need 2 quarts of hot to start a pasta, why wait whilst 2 quarts go down the drain? I like the chili pepper product myself.

[Bob]

I have had the Watts system, purchased from Costco, for about a year and am pleased with it. It saves me time and water by not having to run cold water doen the drain while waiting for hot water. By setting the timer to run only when I need it, the additional energy usage is trivial. The only drawback is some water hammer because of the sensor valve between the hot and cold lines.

The Watts system places the recirculating pump at the water heater and the sensor valve at the fixture at the end of the line. Other brands combine the pump and the sensor valve. One deciding factor is at which location an electrical outlet is available.

[Bob F]

I didn't realize they made commercial systems like that. It is the way mine works, without the temp sensor. When I re-plumbed, I ran an extra return line. I push a button, and the pump by the heater runs for 45 seconds. When you turn the faucet on after that, it's hot within 2 seconds. It's really nice.

[clare]

Complex and innefficient. Best way to have "instant" hot water is to have a small water heater at the point of use which supplies hot water immediately on demand, untill the cold water has come through the pipes. You get HOT water right away, then the temperature drops a little bit if you use more than the capacity of the small heater as the cold bollus comes through, then back to hot.

[clare]

About 2.25 gallons to get hot water to our bathroom. Heater in the bottom corner, bathroom opposite top corner of 2 story house. About 55 feet of pipe to the tub.

[Bob F]

Except the small heater will inevitably be electric, which cost significantly more to run than gas. Pumping a little cold water back to the heater costs next to nothing, and saves water over running the water.

Plus, the extra heater is one more to fail/replace regularly.

[HeyBub]

It's not the best idea to use water from the water heater for human consumption. Water from the heater can contain a goodly number of dissolved minerals and metals, including lead from soldered joints. Over the days and years, all kinds of nastiness from the municipal water supply congregates and settles in the water heater tank. Further, the 140° of a water heater is insufficient to kill most bacteria which flourish in the tank. A few years ago, many at the IRS office in Houston came down with Legionnaire's Disease. The vector was traced to a bacteria colony in the water heater.

The most ghastly condition is to use hot water from the tap to mix infant formula!

Bottom line: Do not ingest water that comes from any water heater. Water heater water is not potable.

[Stormin Mormon]

My church has 3/4 inch water copper from the instant water heater (mechanical room over head) to the bathroom faucets. Takes four minutes to get hot water. I timed it, one cold winter day.

[Stormin Mormon]

My one set of grand parents had a similar thing. Lived in second floor of a house, and she would sometimes leave the water running in the kitchen sink and forget she left it on.

[Stormin Mormon]

I'm going to die!

[salty]

Yes, you are.

[Van Chocstraw]

Another energy wasting idea from the fuel companies.

What you need is a small 6 gallon point of use tank under the sink. Gives you instant hot water and uses little energy. If you use enough hot water the hot water from the main tank reheats the point of use tank so it doesn't even need to heat the water.

[sligoNoSPAMjoe]

Yes it works. There are several different ways of doing it. However how much if any energy that might be saved is questionable.

I have seen versions that constently circulate the water and some that only circulate it when called on (meaning it still takes a little time).

I have not bothered. I do have an instant hot water supply in my kitchen however. Convenient.

[Tony]

Yes... I think we all will.

[willshak]

I am going to live forever, at least until December 21, 2012. :-)

[Tony]

This reminds me of the cheap F*ck*ng Sands Casino in Vegas. (I think it's gone or rebuilt now) With the schedule I kept, I liked to take a shower in the early afternoon. In large buildings they circulate the hot water in a loop or it would never make it to your room without getting cold. It seems to save money they turned of the recirculating after most people where done taking showers. The first day I let the

*hot* water run for 15 minutes and it was still cold. I called to have it fixed and they sent a guy up to verify my hot water wasn't hot. Then he said he would look for the problem. About 1/2 hour later I had hot water. The next day I checked the water temp earlier, called to complain earlier, and it was the same scenario but more time elapsed before I had hot water. Same thing for ? days. On my 2nd last day there I got an idea. As everyone was checking in I made a loud complaints about not having hot water every day. I was creating a small scene, and a few people in line left after I told them they will have the same problem too. I don't recall all what I said but I was on the verge of getting kicked out. Not sure if the water ever got hot that afternoon, but I was OK because I got up early that day to shower. On the morning I checked out, I stood next to people in line and told them to ask if hot water is available all day and told them of my experience. Had a few more people walk out, and some did actually ask if hot water was available all day. After a few warnings I left before getting arrested.

[Robert Neville]

I have a timer based system installed when the house was built, but would like to change to a button based system. Water use is just too unpredictable here! Where did you get your button system?