You’re thinking about purchasing a tankless water heater for your home. You’re ready to enjoy the unlimited hot water and all the other benefits that come with ownership of this unique product.
So, you click on the water heater model that you prefer. It provides the correct GPM output for the needs of your family. The installation looks like it will work with your home’s structure. Even a review of the public comments about the tankless system you prefer shows most people who have used the water heater you want give it glowing recommendations.
Then you look at the professional installation costs of a tankless water system. It tells you this:
Add Expert Installation Today for $1,270.49.
And you gasp. Why? Because that installation cost may be 3x higher than the retail price of the tankless water system you’re thinking about purchasing
Then the next thought happens: is it possible to complete a DIY installation of a tankless water heater?
That’s when there is some good news and some bad news. Advanced DIY homeowners may be able to complete a tankless water heater installation on their own. A gas tankless water heater, however, may need to have the fuel lines put in by local utility technicians.
If you’re thinking about completing a DIY installation for a new tankless water heater, here is a brief summary of what you’ll need to do to complete the job.
Step 1: Remove your old water heater
If you’re replacing an older water heater with a tankless model, then you’ll need to remove the previous unit. Make sure you turn off the water, turn off the electricity or gas, and then drain the older unit to prevent damage to your home.
Step 2: Install the gas line or required breakers
You may need to install a new T-connection and valve if you have a gas connection. If you’re installing a new electrical tankless system, you may need to have a 4 x 40 Amp breaker installed for the system. Most jurisdictions require any new gas lines to be installed by the utility instead of the homeowner.
Step 3: Install your water line
Most tankless water systems will require new water lines, both cold and hot, to run from your existing water supply. Copper pipe tends to work the best for these new lines. Be sure to clean your connectors and pipes before you solder them in place to remove the risks of oxidation. Then apply flux, put the pipe and connectors together, and remember to heat the copper with a torch before soldering the pipes together.
Step 4: Mount the tankless water heater
Most indoor tankless systems must be mounted to perform correctly. That means you’ll need to install a platform along the wall where the system will be installed. You’ll need to have about 4 inches of clearance from the wall for most systems.
Note: A 2×4 does not actually provide 4 inches of clearance. You’ll need to use 2×6 boards if you’re using a standard-sized board to create your platform.
When mounting the system, you’ll also need to choose a location that will allow you to properly vent it.
Step 5: Connect the system
Follow the connection instructions provided by the manufacturer. Make sure you have the shutoff valve and sediment trap connected properly. Attach the power line or gas supply. Connect the water supply. Then bleed your lines and check for leaks. Turn your power back off before moving to the next step.
Step 6: Install the venting
If venting is not supplied already, you’ll need to build your own vent for your new tankless system. Be sure to use stainless-steel pipe for the vent. There will be building codes that must be followed. Because this step may qualify as a building modification, a permit may be required by some jurisdictions.
Remember to use a silicone caulk around the edge of your flange to create a weatherproof seal for exterior components. You’ll want to remove shingles from around the vent hole instead of cutting through them. If you must go through an exterior wall or the roof, remember to replace any shingles or siding that must be modified.
Once you’ve properly vented your tankless water heater, you’ll be ready to turn the system on to test your connections.
Is it possible to complete a DIY installation of a tankless water heater? Yes. Is it recommended for the average homeowner? No.
If you are uncomfortable with any installation task, it is better to hire a professional to complete the job rather than risk damage to your new tankless system, your home, or yourself.
If you haven’t already, check out our top recommended tankless water heaters and their reviews here.