Itching to get your hands on a good do it yourself type project? Something you can do with your own two hands and feel good about when you finish? Here is such a project. It’s not difficult, highly rewarding, and not only is it environmentally friendly, but it ads convenience to your daily life. A win-win if there ever was one.



Fast hot water delivery systems, commonly known as hot water circulating or recirculating systems, provide a number of benefits. Obviously faster hot water means you don’t have to wait as long for it, saving you time. Since these systems do not run water down the drain when delivering the hot water, they save a lot of water.

Running water down the drain is not only a waste of water, but since the water is treated and pumped before it gets to your home, and then the sewer water is treated and pumped, a lot of energy is used in the process. Generation of this energy releases green house gasses into the atmosphere, contributes to pollution, and uses up more of our resources.

The first thing you must do is decide what type of hot water system to install. A full time hot water recirculation system could be a big project since you must run a water pipe from the last fixture back to the water heater inlet. If the plumbing in your home has major branch circuits then you might need to re-plumb some of the hot water piping to get the system to deliver hot water to every sink.

Fortunately there are other types of fast hot water delivery systems on the market that make things much easier for the do-it-yourselfer. There are a number of systems that utilize the cold water line as the hot water return line. Since the cold water line connects to the inlet of every water heater, and to a faucet at every sink, no mater which fixture you are at, you can send water back to the water heater by pumping it out of the hot water line and into the cold water line at that point.

Most of the fast hot water delivery systems put a pump at the fixture and just run the water in a big loop back to the heater. There are some systems that use gravity and thermal valves to move the water, with no pump involved. Although the gravity type systems can work when conditions are right, it’s not practical for most homes, and you don’t really get fast hot water, more like fast luke-warm water. For this article we will discuss only systems that use a pump to move the water.

One popular system is the Laing auto-circ system. This system is another luke-warm type system. The pump is located at the fixture where fast hot water is desired. The pump connects to the cold and hot water lines. A 110 volt outlet is needed, and the pump is supplied with a 6 foot cord. With this system, when the water at the fixture cools down to 85 degrees, the pump turn on and runs until the water at the fixture reaches 95 degrees, and then it shuts off.

Now you have luke-warm water waiting for you, in both the hot and cold water lines. How warm depends upon how long since the last pumping cycle occurred. This type of system uses a lot of extra energy since you have to have your piping at a temperature that is above ambient. Perhaps that is why they include a timer with the pump that allows you to turn the system off when you don’t think you will need hot water. At least it will waste less energy that way. But it kind of defeats the purpose if you ask me. The Laing auto-circ system will not work with tankless water heaters. The auto-circ system runs about $250.00 give or take.

There are other manufactures that make similar systems such as Grundfos, RedyTemp, and Watts, with some variations but basically the same luke-warm type of hot water system. Again these systems won’t work with tankless water heaters and run anywhere from $250.00 to over $500.00.

Another type of fast hot water delivery system is the demand hot water system. Demand hot water systems deliver hot water when “demanded" by the user, usually by pressing a button. A pump is located at the fixture where hot water is desired, and as with the previous systems, connects to the hot and cold water lines. When the button is pressed, the pump comes on, a valve in the pump opens, and hot water is pumped to the fixture at high speed. When hot water arrives at the pump, it shuts off, and you have instant hot water without running any water down the drain. Since the pump shuts off as hot water arrives, very little if any hot water ends up in the cold water line.

You get hot water fast, and you don’t fill your cold water pipe with luke-warm water. Far less energy is used with demand hot water systems than with the other types of circulating systems. Typically a demand system will use less than $ 1.00 a year in electricity costs. Since the demand systems don’t run continuously for long periods or cycle on and off frequently they work fine with tankless water heaters as long as they have a powerful enough pump.

The Metlund D’mand system offers several models and the biggest model will work with tankless water heaters. Metlund pumps run from about $330 to over $800. Another brand, the Chilipepper appliance, has a pump strong enough to run any tankless heater and costs $180.00.

There are some water companies that offer rebates for hot water circulating systems, so check with your local water company…your fast hot water system might end up costing you nothing!

Any of these systems can be installed in less than a day, and for some such as the Chilipepper appliance which connects with hoses, it can be less than 45 minutes.

Of all the systems that use a cold water line as the return piping, the demand systems save the most water, and consume the least energy. All the systems mentioned are recognized by national testing laboratories as meeting or exceeding UL listing requirements.

If you are looking for a great week-end do it yourself project that will provide great benefits for you and your family and help the environment, then a fast hot water system should be at the top of your list.