Hot Water Heater Timer





Introduction: Hot Water Heater Timer

This Instructable is a "How to install" for a Hot Water Heater Timer for electrical hot water heaters. This piece of equipment can save you a lot of money and use less energy helping you steward your footprint on our planet. As of installing it we were able to cut out 16 hours of use on our Hot Water Heater daily... that is a 66% saving on a unit that almost runs constantly and uses a lot of energy. The timer was about $40 then another $15 for conduit and couplers and then a few feet of wiring. Make sure the new wiring is equal to or thicker in gauge to the existing wiring. We will run cost comparisons to see how long it takes for this timer to pay for itself.

Thanks to Canida, he gave a great addition below in the Comments: "A necessary addendum to Step 1: verify this breaker actually maps to your hot water heater. Our breaker box had a full set of labels that turned out to be randomly applied!"

Feel free to check out my blog here!

Step 1: Disconnections

Your next step will be to make all the disconnections:
1. Locate your Power Box on your house and turn off the breaker labeled 'Hot Water Heater', ours was H/W Heater.

2. Remove the plate on the hot water heater then remove the wire nuts.

3. If you have conduit running to the wall then remove the plate and the conduit.

Step 2: Installing the Conduit and Timer

The next steps are to get the timer and conduit installed.

1. Start by locating a stud and then screw a srew in until it is about 1/8" shy of being flush with the wall. (Notice I did not attach the box to the wall permanently, that is why it is at an angle, I attach it later once everything is measured out and dry fitted together)

2. Install the conduit to the original cover plate on the wall. I decided to attach the conduit to the side of the box because the wall mount was directly above the box, it is up to you based on the location of the box.

3. Install the conduit to the box and run the wire through and then trim the wire with about 3-4" excess to be able to attach to the terminals.

Step 3: Wiring the Timer

This step you will be attaching the wired to the Timer.
(Follow the instructions in case they have changed)

1. Pull wires through conduit and strip wires back a 1/2".

2. The wires from the hot water heater will be set to the right terminals, wires from the house go on the left. From left to right, Terminal #1 black from house, #2 black from W/H, #3 white from house, #4 white from W/H.

Step 4: Finish Wiring and Close Up

This next step will be finishing up all the steps of installation.

1. Secure wire nuts as they were before when you started.

2. Attach the ground wire to the ground screw.

3. Attach the Cover plate on the W/H.

Step 5: Setting the Timer

At this point you will schedule the timer and finish.

1. Put on the clear plastic cover over the wiring.

2. To set the time you pull out on the yellow dial and turn it to the correct time of the day. DO NOT adjust the arm that points down 90 degrees.

3. Screw on the 'ON' and 'OFF' adjusters at the correct time and you are finished.



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    25 Discussions

    we bought a house with this timer on the water heater and I want it gone. How do you remove it? Not much of a home repair person so any help would be appre

    Great instructable! I found this to be an excellent resource when I installed my water heater timer. I also found this website to be very useful as well.

    What a great way to save power and cut down on my electricity bill definitely getting a <ahref="">plumber</a> to fit one for me next week

    No one mentioned risk of bateria growth? Tanks needs to be kepts at a constant 60C/140F to prevent legionella disease in stagnant hot water...could result in lung infection/pneumonia, you DO NOT want to turn off your water heater.

    Perhaps add extra insulation, preheat the incoming cold water (there are grey water heat exchanger for this purpose) or go for a tankless/on demand water heater depending on where you're located

    Though not an Intermatic I added a timer to my water heater since I am single and only need to heat water twice a day I have reduced my electric bill in the first month by 50% ! The pay back is incredible.

    I love this. All of the comments have been great and the issues have been real. The HW heater timer is a great way to save money on your energy costs. The catch with all energy saving technology is that the equipment you install it on must be working properly. As an energy management contractor I have learned this lesson the hard way. If you want to know what the ROI is, a HW heater uses about 9.2% of the annual electrical consumtion for the average household. You can do the math and you'll see a 2-3 month ROI. Since I just joined I don't know if I missed an earlier conversation but you can also save money on water heating costs by lowering the temperature to say 120 degrees instead of 140 degrees. 140 degree water will certainly cause you a severe burn and is total overkill. Please keep saving energy every way you can and there might be some left for our children and grand children. Best wishes.

    I'm thinking about doing this, were any of the energy savings posted? I just want to see if it's worth my effort or if it's more of a headache than a money saver.

    Is there a method to test whether or not it is actually working? My husband installed ours the end of Jan and our hot water bill went from 187.00 to 230.00. I'm really conservative when it comes to heat and anything burning electricity so I doubt it has to do with any increase on our end. I was wondering if maybe we had it installed wrong and is there a sure proof way to tell without having to take it off and re-install it. Any feedback would be helpful. Thanks : )

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    2 replies

    A Landlord had one put on years ago & we never had Hot Water, ever? Finally I told her how much the bill was & she could check it for herself. They came back out & the bottom Heating Element was not functioning. So all of the cold water would enter it & move to the bottom. Heat rises, so that why we couldn't get it hot no matter how high we set it. We're thinking about putting a timer on so that we can heat it a little bit hotter then we normally do, then it can cycle from there. Also compare Temp. Days to last years Bill. It should shown on your current Bill. Are you possibly used gaming consoles more? I just read that some of them in Stand-By Mode can cost as much as 2 refrigerators to run!!!A Wii is the cheapest to run. Also, what about Air Conditioning? I've also heard of them wiring it to 1 element instead of both?

    It'll only save you money if it allows you to take advantage of lower electricity rates at off-peak times. Otherwise, it just means the thermostat will have to run the heating elements longer to get the water up to temperature. Insulation and taking shorter showers will save energy.

    dacker, your wish will become a reality. . I have invented one. Look for it on the web in 4 to 5 months.

    Nice! What I was thinkin' was a way of clamping a collar around the temp controller knob on my gas heater and then use a timer-activated solenoid with an escapement, a motor-driven cam, or a stepper motor to change the temp from "night mode" to "normal mode". Part of the trick is to manage the right amount of rotation of said knob.

    This instructable inspired me to install the Intermatic WH-80 model last December. I bought mine brand new off eBay for $20, so it is worth it to look around a little bit and save money. I already see a difference in my electric bill, since we only turn the heater on now for about 7 hours a day. Yup... This timer and an R11 jacket is the way to go. Thanks!

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    I like that we need to install a roof mount solar water heater to pre-heat the water going to the heater. These little things well add up big over a year.

    The only problem with that is if it starts to leak it will ruin your roof. That happened with us and cost a fortune to repair the roof and then you have to replace the the panels. So just keep an eye on them.