Clean water is more valuable than most of us realize. Clean water requires energy, so by conserving water, you're also conserving energy! You can help minimize its waste by installing a foot pedal to control your kitchen sink. We're going to install a couple of solenoid valves under your sink, and wire them up to a simple pedal. It's easier than you think, and you don't need any plumbing or electrical experience to do it. So, let's get started!

(If you like this Instructable, please vote for it! If you don't like it, please vote for it anyway leave feedback below so I can make it even better.)

Step 1: Parts: The Solenoids

The heart of this project is a solenoid valve. Very simply, these are small bits of pipe that have a valve that will open or close when you apply electricity to them. I picked these up on eBay for about $15/ea (here's a search link to help).

Solenoid valves have a few important attributes:

  • the type of voltage required to activate them
  • whether they're open or closed when they're unpowered, and
  • the size or flow rate they will support.

For this project, we're going to want a pair of 12V DC, normally closed valves that will support about 3 GPM (gallons per minute). Typically, the larger diameter of the "pipe", the larger the flow rate. I went with 1/2" solenoid valves, and they're more than adequate for this project.
<p>Has anyone ran into water hammering issues? My downstairs neighbors were hearing all the vibrations and only then I realized that the loud 'thump' was a water hammer. The project was alive for 7 days before I had to disconnect it. Anyone know if w.h. arresters do the trick for typical household pressures?</p>
<p>pjamestx it seems like you started this project about 7 years ago. How have the solenoid valves pushed through the time test? Have you had any leaks or any other problems since you installed them? Also have you had any problems with hot water and the valve's plastic parts? Thanks, this is a great project!</p>
I had this project in place for about two years, and everything seemed to be holding up fine. When it was just me using the kitchen, having a normally-closed valve wasn't an issue, because I was used to how the setup worked. However, when someone else was trying to use the sink, I always had to explain it to them.<br><br>I think if I had switched to normally-open valves, other people could have used the sink normally, and I could have switched the valves on and used the pedal to break the circuit when I wanted to use the sink in conservation mode. However, when it came time to adjust the system, it was easier for me to just remove the valves than it was to find some normally-open replacements. I still have the parts in a box in my workshop, so some day I might revisit this project :)<br><br>Thanks for the interest!
<p>So with a normally open valve, the thing operates like a normal faucet because you manually have to open the valve to let water out. You only need electricity to close it, but does the electricity need to keep flowing in order to keep the valve closed?<br><br>And with a normally closed valve, electricity opens it, which means it only consumes electricity to keep it open, which is less of the time. So this makes more sense, right?</p>
Right, a normally open value stays open when there's no electricity, so water flows through. When you apply a current, it closes for as long as the current is being applied. A normally closed valve is closed unless current is being applied.<br><br>What would probably be ideal is a normally-open valve, where you flip a switch to turn the current on and close the valve, and then the pedal breaks the circuit, so current is no longer being applied and the valve opens back up.
Hello, Use some pedals like the one you find in hospital (ER) non electricity, don't have to recharge the batteries etc.
<p>getting away from electricity leaves you with 2 options either pneumatic / hydraulic valves and a pump pedal or mechanical valves built in a pedal. Hospitals used the mechanical valves in pedal last I checked. Both of these options are kind of expensive, It would be easy enough at this point to hook up a wall-wart wherever your garbage disposal plugs in and boom no more batteries. The whole build would still be cheaper than mechanical foot pedals. If you got the money and the time I'd probably go that route too. Then again the dream build would be the mechanical hot with a temperature controlled cold. This way you have one pedal that automatically goes to the optimum dish washing temperature. that would run $200-$300 and would require some rather interesting piping. Still don't think it would get the wife to help with the dish washing but it would save water.</p>
Those are very expensive, though, and aren't something that can be retrofitted easily.
<p>I'm totally amazed how a innocent kitchen faucet can trigger most insane ecological-political discussions. But, hey, this one certainly served that purpose. :)<br>You didn't expect that, pjamestx, did you. :)</p>
These solenoids are from a clothes washing machine, so if you are throwing out an old machine, you could take them out first. <br>You can buy some spade electrical connectors that crimp onto the wire and then plug onto the solenoid instead of having to solder them. They are much easier to remove if you ever need to replace anything.
From what I know, the washing machines have AC solenoid valves and here they use a 12V DC solenoid valve. Not the same thing I would guess.
In my old workplace, there was a manufactured sink with a bar you step on to activate the water. When your hands were greasy from work you could wash your hands without making because you didn't have to touch the faucet handles. <br><br>I always wanted a similar device. I feel stupid for not building one before. I had this knowledge, but never thought about it. Thanks for the instructable. I'd make one eventually.
Have you encountered any issues with leaving the solenoids under pressure for extended periods of time? Might this have any effect on the life of the part or eventually cause leaks?<br />
That is the purpose of a solenoid. They are under pressure until activated.
It hasn't been a problem so far. I tend to do my kitchen cleaning in batches, right when I get home from work, and again just before bed, so when I'm doing that I'll leave the water on, and I tend to turn it off when I finish up. I have forgotten a couple of times, and turned it off in the morning, and I haven't noticed any problems. The valves I used are closed in their powered-off state, so I imagine they'll be fine, unless you have some crazy high water pressure or something.
Thanks for your great Instructable! <br> <br>Here's an idea that I tried and works like a champ. <br> <br>I wired both the hot and cold solenoid together (in parallel) to a single doorbell button. I mounted the button behind the cabinet door under my sink such that it holds the cabinet door open just a small fraction of an inch. When I need water, I push the cabinet door forward with my knee which depresses the button and closes the circuit. The volume and temperature are controlled with the faucet handle, the flow is turned on and off with my knee. It's nice that no switching device is visible to the casual observer in the kitchen. <br>
Dude your totally Awwwsome
There is a mechanical device which can be retro-fitted to any sink tap( as long as there is a control valve under the sink, with a flexi-hose leading to the sink tap).<br>Have one for several months now. Does not consume power and installation is a cinch with no plumbing experience needed.<br>Check out http://watermiser.hpage.com
Cool, but how does this save more water than regular valves?
All by itself, it doesn't save any water. But I find that when I'm doing dishes or cleaning the kitchen, my hands are often occupied, so I won't bother turning off the faucet when I'm not going to be using the water for a few seconds. With this, I find that I'm much better about stepping on the pedal only when I need the water, so for me it's helped a lot :)
You can get good foot pedals from old broken sewing machines. I happened to get one, and I'm of two minds whether to use the pedal for this or with the nice, heavy motor it came with.
This is so cool. . .and. . .simple.&nbsp; I am building a house and have checked out every sort of peddle valve device.&nbsp; Was about to order the water pressure controlled remote device, but have held off , not only&nbsp; due the the high price but was concerned about committing to custom replacement parts.<br /> <br /> Couple of questions:&nbsp; Think a brass bodied valve might be worth an extra fifteen bucks?&nbsp; And. . . I&nbsp; will install a gfci outlet and a small transformer (doorbell? suggestions?) .&nbsp; Would it be worth the extra complication of switching this outlet to save energy?<br /> <br /> Also I am considering tossing in a couple more valves--they are so cheap-- and hooking them up to a pull out hose with thumb nozel.&nbsp; I could charge it with a wall switch and set the temperature (more or less permantently) with a couple of ball valves under the sink.&nbsp; The idea is to avoid having the hose under full time pressure.&nbsp; Anybody have any thoughts?<br /> <br /> Thanks a ton,<br /> <br /> Willy<br />
Glad you like it!&nbsp; Once I finally got started in this project, it came together surprisingly fast.&nbsp; As far as brass valves go, I don't know how long the plastic ones I'm using are going to last, so it's hard to say.<br /> <br /> You should be able to find a DC &quot;wall wart&quot; that would be compatible, if you don't have one lying around check Radio Shack or a similar place.&nbsp; I'm guessing that having the adapter on a wall switch might end up making it a little harder to use (one more thing to remember).&nbsp; On the other hand, you could always just leave the switch on, if it turned out to be a pain.<br /> <br /> I've been looking for some different valves for the next iteration of this project, but haven't been able to find exactly what I'm looking for yet.&nbsp; If I was going to do this all over again, I&nbsp;would probably find &quot;normally open&quot; (NO) valves, as opposed to the &quot;normally closed&quot; (NC) ones I&nbsp;use here.&nbsp; When other people use the sink, they will forget about the pedal or don't like using it.&nbsp; If I'd used&nbsp; NO&nbsp;valves, the faucet would operate normally until the valves were energized, and the logic of the pedal would be reversed (pressing down on the pedal would break the circuit, causing the valves to re-open).&nbsp; If you're only designing for yourself, then you can have it behave however you like, but if there are others that are going to be using it, you might want to be able to switch it to normal faucet operation (you can accomplish that with my design, but it involves keeping the valves always energized, which seems like a big waste of electricity).<br />
When shaving at the bathroom sink with a razor. I'd love to have foot pedal that activated water at a specific temperature (hot but not scalding) to wash off the blade between strokes.&nbsp; I often find my other hand is covered in shaving cream or otherwise occupied stretching my face into comical shapes and that I'm constantly trying to find the right temperature between water bursts.&nbsp; This would probably save water and speed up the shaving process.&nbsp; I guess in your setup, you can set a water temperature mix and leave the faucet in that position?&nbsp; So really, I'm just advocating for a bathroom sink instillation. <br /> <br /> Also, with respect to neiljackson1984's idea about fixed amount of water, I&nbsp;wonder if the automated soda fountain mechanisms used behind the counter at fast food restaurants would be useful.&nbsp; Many of the worker-used fountains have buttons for fixed volumes (eg. fill this size cup).&nbsp; It may simply be those dispensers have good consistent flow rates and simply need programmed timings in an Arduino.<br />
really nice instructable.....<br /> and great work with the solenoid....<br /> <br /> <br /> im just thinking if i replace the solenoid with something...like a stopper from a **********...it might just work......but think i will leak out......as soon as i solved it i will post my solution.......<br /> <br /> but for now...try to think what is ***************.......its from some where in your basement or in my house its in the kitchen....try to find out....<br /> <br />
You could also switch to 3 pedals: cold, hot, latch. Tapping the latch pedal will open both valves fully, giving you the same behavior as your push-button (manual control). Tapping it again quickly would give you just cold, tapping again quickly gives you just hot. Tapping again quickly shuts it all off.&nbsp; After 1 or 2 seconds, tapping any pedal also shuts it all off.<br /> <br /> I really like the idea of fixed volumes of water being delivered. A tap of a hot or cold could deliver 1 cup. You could just time it if you can't get the flow-meter. 2 taps give 2 cups, 3 taps gives 4 cups.
Anyone figure out how to do it without using ANY electricity yet?(for less than a thousand bucks? some such double-bass drum pedals with pressure sensitive valve whatnot? <br /> wish i knew more about plumbing... <br /> anyone know a good book or site?<br /> <br />
Yeah, check out this <a href="https://www.instructables.com/id/Cozy-Low-Energy-Shower/" rel="nofollow">shower water pedal</a> instructable.&nbsp; It covers a lot more than just the water control, but it might have some ideas for you.<br />
BTW pjamestx AWESOME ible you rock!<br /> <br />
You ask, "what other possibilities are there with a setup like this?". Well, I'll tell you: temperature control and rate-of-flow control. Get two servo-controlled valves that can provide an electronically controllable range of resistance to the flow of water through them. Figure out how to mount a temperature sensor in the output water stream to measure the temperature. Install user-accessible dials for temperature and rate-of-flow. Hook the servo-valves, temperature sensor, and dials to the Arduino, and and then program the Arduino to adjust the servo-valves in order to obtain the dial-selected temperature and flow rate. I suppose you could even add a flow-meter to the output stream, so that the Arduino could precisely control the rate-of-flow. With such a setup, and with a sufficiently accurate flow-meter, and sufficiently responsive servo valves, you could have the Arduino dispense measured alequats of water of any desired volume. This would be great for recipes that call for a given volume of water.
Great minds think alike: I have also had this idea in my head for a while. It's great to see that you've gone to the work of building it.
Seems overly complicated. The same deal could be rigged without electrical components.
I would love to see an all-mechanical version of this, that would be great! Although, I suppose one could also take several years of yoga and then simply manipulate the faucet handle with their foot, rendering both our ideas moot...
I found these - <a rel="nofollow" href="http://www.plumbingsupply.com/footandkneevalves.html">http://www.plumbingsupply.com/footandkneevalves.html</a> - self closing; with the dual pedal version you can press for hot or cold or both together; seems like they simply sit in line between your hot/cold supply lines and taps/mixing tap.<br/>
Although on longer examination those aren't solving for the hot/cold mix as well as pjamestx's solution. They simply turn one or the other or both on... might be able to feather one pedal more than the other to adjust a mixed flow, but that wouldn't be very precise. Mm. Not the 'equal to that but purely mechanical' solution I was hoping for.
Yeah, when I was doing some research, I came across this: <a rel="nofollow" href="http://www.footfaucet.net/">http://www.footfaucet.net/</a> which looks like it solves a lot of these problems, although I don't know how hard it would be to use. Maybe if you took some tap dance lessons you'd be able to mix with just mechanical pedals :D<br/><br/>Part of the reason that I went with this method is that I wanted it to be &quot;open&quot; in terms of being hackable/expandable, and I was looking at hooking up my arduino to it to add further control. I've done some solenoid research, and it looks like it might be possible to get them to open partially, which is the key for mixing, but I just haven't had the time to experiment and get that worked out.<br/>
do show us
"could be rigged without electrical components" - Great! So create your first Instructable and tell us how!
how about adding threaded 'T's before and after each (normally closed) solenoid and using an in-line ball valve for the hot and cold sides. simply reach under the sink and open each valve to set up for using the mixer handle. close the valves to return to foot switched solenoids. with some creative routing of tubing you could mount the valves near the front inside of the sink cabinet to avoid having to get on hands and knees
This is a cool project! However what about considering these things?<br/><br/><ul class="curly"><li>replace the alkaline batteries with some more powerful battery. a nine volt battery in series with two double-a's won't last long. The 9 volt battery has much less current output that the AA's, which means your voltage will quickly drop.</li><li>Get rechargeable batteries and put a waterwheel and generator into your water line and use the flowing water current to charge the batteries! :-) (no, that'd be REAL cool)</li><br/></ul>
Good advice! I need to take some new pictures, I have in fact updated to a pair of 4xAA holders (I only used the 9V because it's what I had on hand), and I will probably look at switching over to a DC adapter pretty soon because the setup has been pretty solid (no leaks, which was my biggest concern). I do use rechargeable batteries and a solar charger, I think the water wheel is a little beyond what I can do :D But I'd totally love to see it if you made it work!
GREAT! and good explaination too! thanks loads!!
I think it's great that you're considering ways to conserve water availability through design! You should check out Carolyn Schaeberle, an Industrial Design graduate whose work, &#8220;Beyond the Tap,&#8221; has developed innovative ways for improving water transport and maintenance in developing countries. <br/><br/>Carolyn, and other sneak peeks from the Pratt Show on May 12-15th, can be found on our blog, Pratt Success! <a rel="nofollow" href="http://prattsuccess.blogspot.com">http://prattsuccess.blogspot.com</a><br/>
The link below seems to be a mechanical version of this, although at a very steep price. <br/><br/><a rel="nofollow" href="http://www.activeforever.com/showproduct.aspx?ProductID=695&SEName=pedal-works-hands-free-faucet-controller-alustra">http://www.activeforever.com/showproduct.aspx?ProductID=695&amp;SEName=pedal-works-hands-free-faucet-controller-alustra</a> <br/><br/> It seems as though this shouldn't need to be that complicated...<br/>
That IS rather expensive to say the least. There is another instructable for a shower which features a less expensive foot operated arrangement using a much less expensive flow device ... <a rel="nofollow" href="https://www.instructables.com/id/Cozy-Low-Energy-Shower/">https://www.instructables.com/id/Cozy-Low-Energy-Shower/</a>. The valve is from here ... <a rel="nofollow" href="http://www.kingssupply.com/item204.htm">http://www.kingssupply.com/item204.htm</a>. I'm sure the spring operated valve shown could be directly attached to a simple foot pedal to do the job. This would probably allow the user to control the rate of flow as well.<br/>
That's really great! I'm totally picturing a sweet setup under my sink with some pulleys in the corners, and a pedal in front tied in to a pulley on each side, so you could step down on the pedal to turn on the valves, and then swing it side to side to control the flow (assuming the valves allow for partial flow). You might fall over if you have to do more than five minutes of dishes, but I bet if he'd thought of it, this is exactly how Mr. Miyagi would have taught Daniel the Crane Technique... "Show me... doing the silverware!"
FYI, a good source of free solonoid valves is old washers or dishwashers. Heck, even a rebuilt one from a parts store is pretty cheap. They are 110 V so you either need to use a relay from a low voltage foot switch, or a foot switch capable of handling the higher voltage. These days, most of them are made of plastic so the chances of electric shock are very small in any event. If you want to be extra protected, plug the system into a GFI outlet as mentioned. I've used them for decades to route water hither and yon with nary a problem. As mentioned, the really safe alternative would be to figure out a way to make a foot operated water valve and route the water through it. That would give you the added benefit of being able to control the degree of flow as well.
pjamestx, that's terrific; hats off to you, this is something I've always wanted to have when washing the dishes (for rinsing). BTW, your comments about beating up planet earth are hilarious. For my project, I plan on using a micon and proxy. Thanks a'plenty for the instuctable. Cheers.
Thanks! The more I use it, the more I realize just how bad I've been about leaving the tap running while doing things (esp. scrubbing down the counter, I was always lazy with that one). Good luck on your project!
I always though pedal taps were just for hygeine, never thought of water savings. Are they usually done electronically? I had assumed they were typically mechanical.

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