How to Install an Electric Water Heater
Installing a new electric water heater (or replacing an old one) may seem like a task reserved for a seasoned plumber…
But for the motivated do-it-yourselfer, this project is actually relatively simple and can be accomplished in less than half a day with tools and materials available at the local big box. Not only will you feel great about doing it yourself, you’ll save about $150-200 on installation, which you can roll right into your next tool purchase!
If you’re about to tackle this project yourself, read on for the complete list of what you’ll need and the instructions to get it done.
(A quick disclaimer: we’re not professional plumbers. Use this advice at your own risk. Your jurisdiction may require a licensed plumber to perform this work. Check local regulations before starting the project. Follow all instructions with the new heater).
Tools & Materials Required to Replace a Water Heater
These tools are basically the same as those required for most copper plumbing jobs, including replacing a copper valve (which we wrote about last week).
Tools
- Propane torch with regulator & sparker
- Low profile 3/4-inch pipe cutter
- Fiberglass heat-stop pad (-not shown, but useful for blocking heat in tight spaces-)
- 3/4-inch pipe cleaner
- Abrasive plumber’s cloth
Materials
- New 3/4″ threaded, flexible water heater connectors (-shown in the pictures below-)
- Appropriate threaded-to-sweated connectors (3/4″ threaded to 3/4″ sleeve-size)
- Silver solder
- Plumber’s flux (& disposable brush)
- Teflon plumber’s tape.
Steps to Replace an Electric Water Heater
Step 1: Turn off the breaker or remove the fuse for the water heater.
Step 2: Disconnect the wiring from the water heater. Usually, romex enters the heater and is concealed behind a plate. The picture below shows the plate removed.
Step 3: Close the valve close to the water heater on the cold line. If there’s no valve or the valve is broken, you can turn off the main water to the house (either inside, or at the street, as a last resort). You should also install a new valve on the cold line with the new heater.
Step 4: Drain the water heater. You can connect a standard garden hose to most heaters and drain into a sump or outside.
Step 5: Unsolder or cut the nearest copper joints on the hot and cold pipes. You can find instructions for soldering a copper pipe at that link. To unsolder, simply heat up the joint until the solder flexes, and then pull the pipes apart. We prefer the low-profile cutter to cut away the pipes…
Step 6: Unsolder, cut, or unscrew the copper pipe from the overflow valve (pictured below)…
Step 7: At this step, the water heater should be completely disconnected from the existing plumbing and electrical infrastructure. Remove the old water heater. Now it’s time to get ready for the new heater!
Step 8: Place the new heater in the old heater’s spot. Make sure the hot and cold lines are aligned with the existing plumbing.
Step 9: Measure and cut new pipes to plumb the new heater in place. Flexible hoses will give you some leeway here. Make sure you consider the threads when measuring the length. Dry fit all components first!.
Step 10: Solder all connections after successful dry fitting. Follow the instructions in these two articles for installing new copper plumbing (how to sweat solder copper pipes) (how to replace a copper pipe valve).
Here’s a shot of the copper pipes during soldering (you can see we decided to install a new ball valve joint on the cold water line to replace the old one).
Step 11: Connect the flexible pipes to the new copper and to the heater. Notice that we used the Teflon Plumber’s Tape to make the final connections from the flexible hoses to the water heater and the pipes above.
Step 12: Reinstall the copper pipe on the pressure release valve. If possible, avoid soldering near the water heater. If it is impossible to avoid close-proximity soldering, be sure to use a fireproof pad as a backstop for the flame.
Step 13: Connect the wiring the the heater according to the manufacturer’s instructions. Some fancier heaters have settings that can be adjusted to achieve maximum energy savings and comfort for your home. If you don’t have the instructions or are looking for some generic instructions, our friends over EZ DIY Electricity have a great tutorial for wiring an electric water heater.
Step 14: Open the cold water valve (and all valves) and allow the tank to fill. Check for leaks.
IMPORTANT! Make sure the tank is completely full before turning on the power. Starting the heater dry can seriously damage the heater and potentially render it unusable.
Step 15: Install pipe insulation on the hot water pipes close to the heater. 3/4″ pipe insulation usually ships with new water heaters, and can be purchased at the local home improvement store.
Step 16: Flip the breaker to begin heating water. You’re done!
What do you think? Got a question, leave it in the comments below!
Comments & Conversation on this Article...
9 Responses to How to Install an Electric Water Heater
July 27th, 2009 6:56 am
Great tutorial Fred! I’ve never seen the flexible hose connections before but that looks like a great time saver! Makes me wonder though if there are any code issues with it? Very cool idea at any rate.
I know you said it above but it bears reminding your readers. BE SURE THE TANK IS FULL before you turn the power on. You can severely damage the heater if you turn on the elements before the tank is filled with water.
[Reply]
July 27th, 2009 9:41 pm
Todd, believe the flexible pipes meet code (they are steel reinforced, and marketed at HD and Lowes with the water heaters… I didn’t check)…
As for the warning, it’s a good one so I added it to the article. Thanks!
[Reply]
July 29th, 2009 5:48 pm
You should add to your tool list plumbers pliers or adjustable wrench to tighten fittings that are threaded and also a pair of wire strippers.
[Reply]
September 23rd, 2009 1:18 am
Allen, thanks for the tip!
[Reply]
November 25th, 2009 7:50 pm
Thank you representing details. It helped me in my assignment
[Reply]
June 6th, 2010 3:04 pm
Very great Instructions and very detailed pictures. id like to add tho before u drain water heater make sure u turn on a hot wateer facuet or u can damage ur pipes from it creating a vacuum. especially on older homes with older piping. and to tell if the water heater is full to turn on power u can also turn on hot water faucet and once water comes out. it is full.
[Reply]
November 23rd, 2010 8:40 am
When I did my first hot water heater I used a propane torch. My solder joints were very poor. I enlisted the help of a plumber friend who told me to toss the propane can and instead use a can of MAP gas.
The MAP gas burns much hotter and made sweating pipes a breeze compared to trying to do it with propane.
[Reply]
November 6th, 2011 8:56 pm
Thiking about moving electric water heater from kitchen to garage. How far does heater have tobe from circuit box. By code. Any help would be great. Live in NM
[Reply]
Fred Reply:
November 15th, 2011 at 7:22 pm
Depends on a lot of factors – including gauge and grade of cable being run between the breaker panel and the unit. You should get an electrician to give you an estimate for your particular situation.
[Reply]