Stop running water down the drain and get Faster hot water.
Having instantly available hot water at the fixture when you reach for the faucet saves you not only time, but water as well. You don’t have to stand there running water down the drain while you wait.
Hot water on demand pumps can save you energy too!
Lots of folks have fixtures so far away from the water heater that they turn on the hot water and go do something else instead of standing there waiting. When they return the water is hot. That means they have been running hot water down the drain. The energy to heat water is much more expensive than the water itself. This is a huge waste of energy and contributes to the emission of green house gases as well. An instant hot water system eliminates this waste of course.
Get cleaner dishes!
Instant hot water systems can even result in cleaner dishes! The leading cause of dishwasher problems is that the water often is not hot enough to completely dissolve the dishwashing detergent. By insuring your dishwasher gets hot water you will have sparkling clean dishes.
Choose the right pump
There are a number of “instant” or “fast” hot water pumping/distribution systems on the market, and it’s important to choose the right system for your particular application. Some use pumps, some rely on thermo-siphoning, and not all systems will work will all types of water heaters.
Some of these systems manufactured by Laing, RedyTemp, and others place a pump and valve combination at the fixture furthest from the water heater. The system pumps the hot water in a big loop, out of the water heater to the fixture, through the pump, through the cold water piping back to the water heater. The pumps have very slow pumping rates. When the valve between the hot and cold water lines detects hot water it closes. This keeps the water at the valve at about 95 degrees.
The problem I have with this type of system is that it is really a “luke-warm” system. Ninety five degrees is below the human body temperature so it actually feels like cool water. Since you are not starting with cold water, the pipe being full of luke-warm water, it won’t take quite as long for the hot water to reach the fixture, but it certainly is not instant hot water! The pumping system is cycling on and off constantly all day long, and so it keeps the piping (both hot and cold) full of warmer than ambient temperature water. This makes the water heater work harder, and uses significantly more energy than a standard plumbing system. The pumps run for long periods too, so add that energy into the mix.
Traditional recirc or reticulating pumps don’t usually work with tankless water heaters
These systems will not work with tankless water heaters. Tankless water heaters require usually 1/2 gallon per minute or more to being flowing through the heater before it will turn on. The Laing and RedyTemp systems don’t pump enough water to turn on the heaters.
Another type of system puts the pump at the water heater and a valve at the fixture furthest from the water heater. The pump creates a pressure difference between the hot and cold lines, and so when the valves under the sink open the water flows through into the cold water lines and back to the water heater inlet. The valves are temperature controlled and close when they detect that 95 degree water. The Grundfos system allows the placement of more than one valve, even one for every fixture if so desired. Watts makes a similar system but you only get to use one valve at one fixture. These types of systems often include a clock timer with them so you can shut them off when you aren’t going to use them. It can be a pain when the power goes off and the clock gets screwed up.
Like the previous systems, these systems also keep the hot and cold water lines full of warm water and thus waste tremendous amounts of energy. As with the previously mentioned pumps, these can not be used with tankless water heaters for the same reasons.
Hot water on demand systems are the better choice
If saving water and being energy efficient are important to you then you will want to examine “Demand” hot water systems. On demand systems deliver hot water rapidly to the fixtures upon demand. When you want hot water you push a button, and the hot water is pumped at high speed to the fixture. When the hot water reaches the fixture the pump shuts off keeping hot water out of the cold water pipes. Now you have instant hot water, nothing was run down the drain, and you didn’t waste any heat energy keeping the pipes hot all the time.
Metlund makes a system called a D’mand system with a number of models. They range in price from a little over $330.00 to over $500, and have a number of accessories like using motion detectors to turn on the pump. Metlund’s largest D’mand system will run most tankless water heaters.
Chilipepper Sales has an on demand system called the Chilipepper Appliance. The Chilipepper Appliance has the most powerful pump on the market, and will work with any tankless water heater. It will in fact work with any storage type water heater as well. The Chilipepper is the least expensive of the systems at $180.00.
I think one of the best things about having an on demand hot water system is that whenever I use hot water, and I push the button to start the pump, I feel so darned good about not running all that water down the drain.