# Energy Efficient Plumbing

While standing over your running faucet, do you ever think about what a shame it is to waste all of that cold water while you wait to feel hot water emerge? Sure you do. (…)

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## Related Questions:

### why does it take two bowls of water before water gets hot

How quickly the water coming out of any specific faucet "gets hot" is most often a function of the distance from the water heater. A faucet that is a significant distance from the water heater must first allow all the cool/cold water in the lines to flow through before the hot water will begin to flow from the faucet. You can estimate that distance. look here:
http://waterheatertimer.org/pdf/How-far-hot-water-travels-in-household-pipes-in-30-seconds.pdf

The wait can be solved to some degree with a continuous flow pump, but this uses (wastes) lots of energy. Installation of a tankless heater in close proximity to the faucet can also solve the "problem". Be sure its is capable of raising the water temp at the flow rate as you require.
Waiting for Hot Water

Jan 29, 2015 | Water Water Heaters

### getting hot water when shower valve is first opened.

If I understand correctly, you have single handled shower faucet.
Normally there is a wait for hot water to arrive at faucet.
But now hot water is already at shower faucet.

Single handled faucets have a mixing area inside valve where hot and cold come together before going into sink.
This mixing valve can have crossover where the hot and cold can pass through to each other even when faucet handle is off. When single handle faucets get old, this can happen.
How it happens:
For example another faucet is turned on inside house, and pressure differential between hot and cold causes hot water at shower handle to pass through mixing area and into cold water line.
So if another faucet has been run, then that lets hot flow to faulty single handled shower faucet.
To confirm this is the problem: turn on other faucet and put ear against shower faucet to listen for moving water.
This condition may also signal there is a water leak.
The problem is not harmful, but will draw cold water into water heater each time, and is energy wasteful.
Replace faucet or have plumber repair problem.

Feb 19, 2011 | Price Pfister Single Lever Handle Faucet...

### i have a single control, new glacier bay bathtub faucet control. i don't have the hot water heater hooked up. i'm only getting a slight trickle out of my faucet whenb i turn the knob to cold. is it necessary to have pressure going to the hot and cold water side to work ?

it is likely required. many new faucets have what's called a pressure balance valve that helps prevent scalding by lowering the pressure of hot when the cold pressure drops (due to a toilet flush or other water being run). Because you have pressure to only one side, that can cause the valve not to provide the necessary volume.

Dec 12, 2010 | Plumbing

### I have replaced my electric water heater and I have checked everything I can think of and I still run out of hot water in 3 minutes. What on earth is the problem.

3 minutes?? does the water run cold then? or just warm?
Is this what the tank you replaced was doing? If so, then you may have: 1 a recirculating pump instant hot water system thats faulty and allowing cold water backflow into hot water piping. 2 A tempering valve that has stuck, allowing cold water into your hot water system.
Or maybe a broken or missing dip tube in your new heater.
If after 3 minutes the water is coming cold out leave that faucet running and go to heater and feel the hot water outlet pipe from the heater. if that pipe is hot then the heater is not the problem. If the hot pipe from the heater is cold the heater is the problem. (Make sure the cold pipe coming into the heater is connected to the Right side marked "cold" !) If there is a tempering valve by the heater: feel the output from the tempering valve, if it is cold and the pipe from the heater to the tempering valve is hot, then the tempering valve is the problem. If all these are OK somewhere in your plumbing system hot and cold may be connected possibly a faucet or showerhead that is shut off at the spout/head, but hot/cold handles are left turned on then cold water can backflow thru hot pipe.

Jan 18, 2010 | Rheem 40 GAL ELEC TALL Water Heater 6YR SC...

### Water is either hot or cold - no in between.

I found a way to get warm water in the shower, but I'm not sure it qualifies as a solution. After trying everything else I thought that maybe when I was feathering the faucet in the shower toward the cold side so I would get warm water that at a certain point it blocked the flow on the hot water side enough so that the sensor in the hot water heater sensed there was no demand in the line and it shut the water heater off. To test this, I went to the kitchen and turned the kitchen sink faucet all the way to the hot side and then turned it on so that I got a small flow of water. I waited for the water to get hot to be sure the hot water heater was working. Once it was hot, I left it running to keep demand in the line and then I went to the shower and turned the faucet on. When the water got hot I started feathering the control towards the cold side and soon I had warm water. So I think I'm right in that the sensor in the hot water heater was shutting the water heater off when the demand in the shower was lowered to a certain point when I was trying to adjust the water temp in the shower.

So now I can get warm water, but it means I have to leave the hot water running at another fixture in the house to create a false demand in the system so the hot water heater doesn't shut down. Is there a way to adjust the senor in the hot water heater so that it will stay on when I'm using the shower only, so I don't have to waste water by running another faucet when I want to take a shower?

Nov 28, 2008 | Water Heaters

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