Water heaters typically last about 10 to 15 years. That means, if you buy a home you are likely going to have to replace it at least once. And if you pay to have it replaced, you are going to be paying more to install it than for the water heater itself. So, why not just install it yourself?
Depending on the state and city regulations and codes, a homeowner can usually replace a water heater on their own, legally. In some areas, you may need a permit, but that’s it. However, you really need to know what you are doing. This job is for the more advanced DIYer, especially if you are dealing with gas.
If you ask the experts, some will tell you to go ahead and do it on your own while others may say no way. Of course, some of those experts may just be wanting to do the job for you because it means more money in their pockets. The best thing to do is to check with your city building department or city hall to make sure it is okay first.
Table of Contents
- Before Starting the Job
- Ready to Install?
- Step One: Turn Off All the Power
- Step Two: Gather Your Tools and Materials
- Step Three: Measuring the Space
- Step Four: Draining the Old Tank
- Step Five: Unhooking the Old Tank
- Step Six: Getting Rid of the Tank
- Step Seven: Installing the Water Heater
- Step Eight: Hooking Things Up
- Step Nine: Connecting the Gas Line (for gas water heaters only)
- Step Ten: Turning Things On
- Step Eleven: Checking for Leaks
- Step Twelve: Lighting It Up
- Related Questions
Before Starting the Job
Once you get the permit situation sorted out and you are given the green light, you need to know the dangers of installing a water heater first. There are some things you have to know.
Turn Off All the Power First
One very important tip before you do any kind of work is to make sure all the power is off to what you are working on. This means electricity, gas, and water. Even if you have a gas water heater, it uses electricity too.
Make Sure You Have the Correct Size
If you want a bigger tank because you hate running out of hot water, check with the city codes first. Some jurisdictions only allow a certain size tank. On the other hand, you do not want to get too small of a tank either.
- A family of two with one bathroom will do fine with a 30-gallon tank.
- A home with a family of four with three bathrooms will need a 50-gallon tank.
- Those with a larger family and many bathrooms may need more than one water heater.
Temperature and Pressure Relief (TPR) Valves Are Essential
If you do not install a TPR valve in your water heater tank, it can explode. Period. The TPR valve is there to let the excess pressure out of the tank when needed. Without it, the pressure can build up to dangerous levels and an explosion is imminent.
The Dangers of Gas
When dealing with a gas water heater you have to be extra careful. Improperly connected gas lines can cause a leak, which is another risk of explosion. You also have to connect your gas water heater to a flue to vent the gas and prevent carbon monoxide leaks. Take care to get a professional if you do not feel confident in hooking up the gas.
You Cannot Just Put It Wherever You Want
Almost all states have an International Code Council that has specific rules and regulations about where you can and cannot put a water heater. For example, you cannot put a water heater in a storage closet. And if you put it in a bedroom, it has to be in a sealed enclosure.
There are all kinds of bacterial contamination worries when it comes to dealing with water supplies. This is the water you and your family will be using to bathe, drink, and cook with. One dangerous bacterium is Legionella pneumophila, which grows in water between 95 and 115 degrees. That means your water heater should be set to 115 or more to prevent this bacterium.
Ready to Install?
If you have gone over all the dangers and still want to install your own water heater, follow the steps carefully. The first step is to turn off all the power as we mentioned earlier.
Step One: Turn Off All the Power
Turn off the water, electricity, and gas to the water heater before doing anything else.
Step Two: Gather Your Tools and Materials
You will need quite a few tools to do this job properly. These tools include:
- Pipe cutter
- Moving dolly
- Pipe wrenches
- Tape measure
- Plumber’s tape
- Wire brush
- Piping compound
- Connectors and fittings
Step Three: Measuring the Space
Unless the new tank is exactly the same size as the old one, you need to measure the area to make sure the new one will fit before starting.
Step Four: Draining the Old Tank
Hook up your garden hose to the drain valve and empty the tank outside, into a floor drain, or into several buckets. If you turn on the nearest hot water spigot, the tank will drain faster.
Step Five: Unhooking the Old Tank
After double-checking that the gas, electricity, and water are off, use your pipe wrench to disconnect the gas line. You should disconnect it at the flare fitting if it is copper and at the union fitting if it is steel. Disconnect the water lines above the tank next.
Step Six: Getting Rid of the Tank
Unhook the gas exhaust from the vent hood by removing the screws. Leave the venting where it is as long as it is not rusty or damaged. Use the moving dolly to remove the water heater. This may take two people if it has a lot of sediment inside of it.
Tip: You may be able to find a recycling center nearby where you can take your old water heater.
Step Seven: Installing the Water Heater
Put your water heater inside a drain pan to collect water if it leaks. Align the water heater so there are six inches of space on each side but enough room to access the controls and burner. Use your level to make sure it is leveled out. Hook up the flue to the exhaust vent.
Step Eight: Hooking Things Up
Put plumber’s tape on the heat trap pipe threads before attaching. Hook up the red fitting to the hot water line with the arrow pointing away from your water heater. Hook up the blue fitting to the cold-water line with the arrow facing into the water heater, tightening them with your wrench. Hook the water back up.
Step Nine: Connecting the Gas Line (for gas water heaters only)
Clean all the threads with a wire brush and apply the piping compound to the black pipes as you attach them. Tighten them with your pipe wrenches. Do the union fitting last because it hooks up the new line to the old line.
Step Ten: Turning Things On
Turn on the water supply and open the valve to fill the tank. Be sure to turn on a hot water faucet to bleed the air from the pipes. Next, you will turn on the gas supply valve.
Step Eleven: Checking for Leaks
This is extremely important if you have a gas water heater. Test every gas connection before continuing. To do this, you can fill a spray bottle with water and dish soap and spray it on the fittings. Wait and see if any bubbles form. If you see bubbles, you will need to redo that fitting and retest.
Step Twelve: Lighting It Up
Remove the access panel to the burner and turn the control knob to “pilot.” Light the pilot light with a BBQ lighter or long match and press on the reset button for 60 seconds. Turn the control knob on and the burner should ignite. Put the access panel back on and set the temperature at about 120.
What if My Water Heater is Leaking?
Check the drain valve to make sure it is not left open. If that is not the cause, check all of your connections again. Listen for a whistling sound near all of the pipes and around the tank. Any weird noises may mean a leak somewhere.
What if My Water is Still Not Hot?
If the water is not hot after a few hours, you should shut off the water heater and check all of the connections. Go over the above steps one by one to make sure everything was completed properly. If it still does not work, call in a professional.
Important: Make sure the TPR valve is working properly and keep checking it for a few days just to be safe.