Removing a water heater thermostat is not too difficult, once the preparation is complete. Double check with a tester to make sure the power is off before proceeding.

To work properly the electric water heater thermostat needs to be positioned firmly against the wall of the hot water tank. It is held in place by a spring steel bracket. There are no screws that actually hold it in place.

You have followed Steps One and Two, so the power is off and the cover plates have been removed. You have removed the insulation and the plastic shield. There are different wiring configurations depending on your model. You will want to tag the wires before you remove them.

In addition, I suggest that you take a picture of the wires. Remember that old 'a picture is worth a thousand tags' thing. Actually it was 'thousand words', but you get the idea. Take a digital picture with your phone or camera. You may thank yourself later.

Remove the wires when you have the proper documentation. You may need to pry back on the clips to get the thermostat loose. Don't bend them, you will be sorry. The new thermostat will need to be pressed tightly against the tank.

Some water heaters have a break away clip that acts as a further restraint. Are you baffled and can't get it loose. Check your owner's manual. If it has one of these, it is probably a newer model. Don't throw the old electric water heater thermostat away. You want to take it with you when you get the new one.

Adjusting a water heater thermostat is a little harder than adjusting the thermostat on your furnace. This thermostat is meant to be set once and left alone, usually, the factory settings are suitable.

Not sure if this is your problem? See the article 'Troubleshooting Electric Water Heaters' for a complete listing of all of the problems related to an electric water heater.

Too Little Hot Water

Are you thinking of raising the temperature because you don't have enough hot water? Raising the temperature is not the way to solve this problem.

It is likely that you have another issue. The thermostats themselves may be malfunctioning or you could have a burned out heating element. See the articles 'Testing Electric Water Heater Thermostats' and 'Testing Electric Water Heater Elements' for information on checking to see if these items are functioning properly.

Safety Concerns

For safety reasons the water temperature adjustments for your electric hot water tank are hidden under a couple of layers. Make sure you follow the 'turning off the power' guidelines for electric water heaters. You will be very near some wires that have serious current in them when you make this adjustment.

There is a danger in setting the temperature too high. Water that is set to 160 degrees will give you a lot of hot water. It can also cause a serious burn in less than a second. Especially when there are children in the home should temperatures be set conservatively. Most manufacturers recommend a temperature setting of 120 degrees. Your water heater is likely set by the factory to that temperature.

See the article on 'Hot Water Heater Temperature Settings' for information on the correct settings and why setting it too high can be dangerous. Do you really want to change it?

Shutting Down the Water Heater

You need to shut down the power to the water heater before you attempt to access the thermostats. See the article 'Shutting Down an Electric Water Heater' for more information. Pay particular attention to the segment on shutting off the power.

Double check and make sure the power is off at the heater and make sure you tag the breaker.

Locating the Thermostats

Most water heaters have two thermostats. The are attached to the side of the tank. The locations of the thermostats are beside two removable plates on the side of the water heater.

You have to remove the metal covers on the outside of the hot water tank first. Then you will find some insulation that has to be removed or pushed aside to expose the thermostats and elements. Most models have a plastic cover that serves as an additional protection. You will need to remove the plastic cover to make the adjustment.

Adjusting The Thermostat

There is a screw that the can be adjusted with a flat blade screwdriver. The heat descriptions may vary. It may have the actual temperatures. Some of them have letter designations (A, B, C), while others may have the words 'Warm' or 'Hot'.

Summary

It is not common to need to adjust the temperature on your electric water heater. The factory settings are adequate in most situations. If you are not getting enough hot water, raising the temperature is not the solution. You likely have another problem such as a 'burned out element' or a 'faulty thermostat'.

An obvious reason for interest in electric water heater thermostats is the temperature of your hot water. If you need to adjust the water temperature, the thermostat is the place to do it.

Most of the time, the thermostats get some interest when you have too little hot water or no hot water. The thermostats could be part or all of the problem.

Not sure if the thermostats are the issue? See the article on 'Electric Water Heater Troubleshooting' for descriptions of all the common problems and a listing for resources on how to fix them.

The thermostats are closely related to the 'heating elements' and testing and checking should inolve both components.

How Electric Water Heater Thermostats Work

An electric water heater thermostat tells the heating elements when to heat up. Most electric hot water tanks have two elements and two thermostats. The elements do not heat up at the same time. The top element heats the water first and then the bottom element kicks in.

The upper thermostat acts as a coordinator between the two elements. When the water in the top part to the tank is hot enough, it lets the lower thermostat go into action. When the lower thermostat senses the water is too cool it turns on the lower element. This happens only after the upper element has finished heating.

You need to do some testing to determine which element or thermostat is bad.

There is another reason you could be here. To adjust the temperature of the water you need to get to the thermostats. These thermostats are a little harder to adjust than your furnace is. There are a couple of things you need to do to expose them.

Electric Water Heater Thermostat - Information

The upper thermostat is around $20 to $25 and the lower one is $10 to $15. You will probably pay around $100 in labor to get them

How Hard Could It Be?

Replacing an electric water heater thermostat is not that hard of a job. You are dealing with some serious electricity and that adds a safety factor.

• Difficulty Level of: A Bit of Work
• Skill Level of: Determined Handyman

For and explanation of the terms in this section, see 'How to Use This Site'.

Check the Simple Things!

Try the reset buttons before you replace the thermostats. Each thermostat has one.

Do not work on the wiring for an electric hot water heater with the power on. Make sure the breaker is shut off and taped or locked in the off position. The current in a hot water tank can kill you. Replacing the wrong thermostat may still leave you without hot water or not enough hot water.

Electric Water Heater Thermostats - Safety Issues

Before you test or work on electric water heater thermostats or the water heater in general, you want to make sure that you have shut off the power to the water heater. The electrical power that heats the water can cause serious injury or even death.

See the article, 'Shutting Down an Electric Water Heater' and 'Electrical Safety Tips' for more infomation and the proper procedures to follow when working on an electric water heater.

Troubleshooting Electric Water Heater Thermostats

Is it safe to work on electric water heaters?

It is not safe to work on an electric water heater without taking certain precautions. Before you do anything, you should shut down the power to the heater. See the article 'Shutting Down an Electric Water Heater', and review the section on safely 'Shutting Off the Power'.

Water heater thermostats are connected directly to the hot water tank. The tank will likely be hot. See the section on 'Cooling Down a Hot Water Tank' in the article 'Shutting Down an Electric Water Heater' for information on lowering the water temperature in the tank.

How do I adjust the water temperature?

The electric water heater thermostats have a dial on them that you use to adjust the water temperature. The article on 'How To Adjust a Water Heater Thermostat', discusses this topic in detail. Do Not raise the water temperature to generate more hot water. The factory settings will at a safe level. Raising the temperature can cause burns and scalds and should only be done using extreme caution.

If you have too little hot water, the temperature setting is not the problem. The thermostats themselves could be causing the trouble. See 'How To Test Electric Water Heater Thermostats' for more information. It could also be a bad heating element, see 'Electric Water Heater Element Testing' to learn how to check the elements.

Not sure what you problem might be? See the article, 'How To Troubleshoot Electric Water Heaters'.

How do I test a thermostat to see if it is working correctly?

You want to see the article on 'How To Test Electric Water Heater Thermostats' for information and the correct testing procedure.

How do I replace an electric water heater thermostat?

To replace a thermostat, you will need to remove the old one. The article 'Installing a Water Heater Thermostat' Will provide you with instructions on removing the old one and installing the new one.

Where can I purchase a new water heater thermostat? How much do they cost?

Another challenge you will face is obtaining a new thermostat. The section on 'Purchasing a Water Heater Thermostat' in the article 'Installing a Water Heater Thermostat' will you some guidelines on how to obtain one.

How do I find out if my water heater elements are bad?

Another closely part is the heating elements. If the thermostats are working properly and you still don't have hot water, one or both of the elements could be bad.

See the article on 'Electric Water Heater Element Testing' for information and procedures to follow.

Summary

There are basically two reasons for being concerned with an electric water heater thermostat. The first and easiest is to adjust the temperature. Unless you have some unusual circumstances this is not needed most of the time.

The other more common problem is that one or both of the thermostats is malfunctioning. Hopefully this informatin pointed you in the right direction for a solution.

Is an electric water heater installation something you can do? First you need to make sure you really need a new one. Are you sure your water heater needs to be replaced? Have you checked on possibly fixing it? Water heaters can last ten to fifteen years. Is yours older than that? Installing a new electric hot heater is a big job for a homeowner. Yes it can be done in a day if things go well.

Before you decide on a new electric water heater installation you want to make sure you can't repair the one you have. See the article Electric Hot Water Heater Troubleshooting for things you can check on.

This article covers the installation of a standard electric hot water heater. These are the lowest cost to purchase and the easiest to install. Energy star rated heat pump hot water heaters cost a lot more and are more work to install. We are going with the, 'you are in a jam' reasoning and assuming that you need to get it replaced as economically as possible.

Electric Hot Water Heater Installation - Information

Selecting a New Hot Water Heater

Electric hot water heaters come in different sizes. Getting one with that is the same height will make a huge differences on how hard the hook ups are going to be. A key dimension is the height of the top of the water tank from the floor. It is not the end of the world if you can't find an exact match. It just means that you will have to modify the piping.

The next concern is the cost. Gas hot water heaters can range in cost from around $250 on up to $1,800 for a high efficiency model. In this article we will make the assumption that you are going for a less expensive standard model. These should be in the $250 to $600 range.

Watch where you buy your hot water tank. Some online vendors and specialty stores have disclaimers that void the warranty if you install the hot water heater yourself. The home supply stores that cater to do it yourself customers, have warranties without this disclaimer. Obviously they exclude improper installation and incorrect usage.

Water heaters are a big item and will not fit in the trunk of a car. In addition they are glass lined and should be handled with caution.

Some ancillary items that you might need would be: (1) Dielectric unions or nipples. Some water tanks come with these installed. You will have to check with your building department to find out if these are required. (2) Pressure relief valve. Some new water heaters have them pre-installed, others do not. A drip pan, these are suggested and required in some places. You may also need misc. fittings to make the connections.

Removing an Old Electric Water Heater

Removing your old hot water heater is part of an electric water heater installation. The first thing you want to do is turn off the power to the water heater. Shut off the breaker to the hot water heater. Put some tape over the breaker to notify anyone that you are working on it. Next run some hot water in a sink nearby until the water cools down (if the water heater is not working you can skip this step).

Shut off the cold water inlet valve and leave the hot water faucet open in sink nearby. Hook a garden hose up to the drain valve near the bottom of the tank. Run the hose to a floor drain or outside and open the valve. After it has drained down a little way, you can open the pressure relief valve and shut off the faucet.

At this point you can unhook the electric lines. There is a cover plate on top of the water heater where the electric line comes in. Remove the plate. Use a non contact voltage tester to make sure the power is off. You should have three wires that are connected. A black, white and ground. Unhook them after you are sure the power is off. You will want to save the connector that attached the flexible cable to the water heater. Loosen the lock nut and remove the plate. Put the wire nuts back on the bare wires for now.

Next would be the water lines. The cold water inlet and the hot water outlet. Again you should have unions not to far above the tank. Loosen the unions with two pipe wrenches. You should remove the fittings and nipples at the top of the tank as long as they are in good condition. One more item you will want to salvage is the drain tube that extends down from the pressure relief valve.

This is where you need the helper. Get some help to remove the old tank. Disposing of it might be a chore in itself. For now you want to get it out of the way.

Setting a New Water Tank

The next step in an electric water heater installation is unpacking the new unit. It is best to do this out away from the area it is being installed. There should be some instructions that come with it. Read through the instructions and look for any special items that need to be attended to. Be aware of any temporary plugs or shipping braces that need to be removed.

Are you installing a drip pan. Put in place before you try to set the water tank. Using some help again carry the new water tank into the location and set it in position. Turn the tank so that it is oriented the same as the old one. The hot and cold water lines need to line up.

At this point you find out how much trouble you are going to have with the fittings. Check the water line nipples. Are adjustments needed. For a tank that has dielectric nipples installed you will need a coupler and possibly a reducer. The nipple length may be off. Measure from the inlet and outlet on the water tank up to the bottom of the union. Make yourself a little sketch with the dimensions. You may have flexible connections here. Some building departments allow it. If you do that is a lot easier.

Mark your sketch with the fitting types, male, female and union and to what point on the fitting you are measuring to. Oh, almost forgot, size of pipe, either 1/2" or 3/4" or a combination of the two. I know this is a little tedious, but it is a necessary step in an electric water heater installation.

Are you ready for a trip to the supply house? Take your sketches with you and go to a home supply store that does pipe threading and has a plumbing department. Ask for help and explain your situation. They should be able to cut and thread the pipe for a nominal sum. In addition they can get you the right fittings to make the connections. Get some suitable joint compound while you are there.

Installing the Wiring

Hooking up the wiring is pretty much the reverse of what you did to unhook it. As long as your new unit is approximately the same size as the old unit. You will attach the flexible cable connector to the knock out in the cover plate. Use a screwdriver to remove the 'knock out' from the plate.

Remove the cover plate from the new electric water heater. you should have two hot leads and a ground lug inside the cavity. Use wire nuts to hook up the hot leads. Check the wiring diagram in the instructions. There will likely be a grounding lug to hook the ground wire to. Check the diagram. With the wires secure you can put the cover plate on.

Hooking up the Water Lines

Water line hook up in an electric water heater installation is e lot easier when you have the right fittings. Again you should use pipe joint compound on the threaded connections. Be sure to remove the plastic caps. Work from the water tank up toward the unions when tightening things. Make sure the connections are tight. Hook up the unions and that should be it.

Then last item would be the pressure relief valve. Again use some pipe joint compound on the threaded connections. Tighten the relief valve with the outlet turned down. Install the outlet tube that you took off the old unit.

Starting it Up

You have to fill the hot water tank before you can turn on the electricity. Open a hot water faucet nearby and turn on the water. Let the tank fill until all of the air is bled out of the tank.

Check for leaks and tighten anything that is leaking. When the hot water tank is full you can turn on the breaker.

The tank is cold so you will get some condensation. This should stop after a day or so. It will be some small drips of water that may make it to the floor.

Electric Hot Water Heater Installation Summary

Now that was a big job. You might be a little tired, but you likely saved $300 to $500 doing the work yourself. Was it worth it? You will have to be the judge of that. I have heard horror stories of homeowners that were sold hundreds of dollars of additional parts when the plumber came out to actually install the heater. You may have saved even more.

With this experience under your belt you are ready to tackle just about any home repair project. What will you do now? For today a little rest is in order. Tomorrow, who knows.