Installing a Gas Tankless Water Heater Yourself

How to Install a Gas Tankless Water Heater Yourself

If you have finally decided to go with a tankless water heater in your home, we only have one thing to say: how come it took you so long?

Joke aside, tankless water heaters have been all the rage for some years now, and many people use them for quite some time.

Assuming that you’ve already selected your tankless water heater, you should continue with installing it. The first thing to do is to make some preparations.

How do you need to prepare before installing the tankless water heater?

Anyone having to replace the old water heater should begin with some preparations. The last thing you want is not to have hot water for a couple of weeks until everything is done. Here are some aspects to consider:

  • Do you install a new gas-fired unit?

Should you install a new gas-fired tankless water heater, you have to check to see if the gas meter upgrade is necessary. It’s because gas-fired units require a lot of BTUs, and the current meter may not have enough capacity to support it, along with all the other gas-based appliances in the household. Just get in touch with the gas company; they will upgrade the meter if needed for a little or no money at all. The gas company should also offer the proper amount of manifold pressure you need for the unit.

  • Is a new gas line needed?

When you must install a new gas line, it’s recommended that you hire a professional plumber. A couple of black gas pipes should run to the unit. Moreover, you may also have to have another gas shutoff valve installed before installing the water heater.

  • Don’t forget about venting!

We should also remind you that indoor gas-fired units need venting because the water heater will cause impressive condensation. It presses air out with a fan, therefore category II stainless-steel exhaust pipe featuring silicon joints can work.

  • Is the climate cold in your area?

Any person living in a cold climate also has to buy a damper, lowering the risk for the cold air to come back in. A condensate drain should also be installed, draining water from condensation through some plastic tubing that can go to a utility sink or a floor drain. The best idea is to check the manufacturer’s manual about the correct venting. Several elbow fittings may be needed for routing the vent pipe inside the unit.

  • What is the electrical power?

Most gas-fired tankless water heaters require 120-volt electrical power. It’s better to plug it into a close outlet or wire it straight to the junction box.

  • Is the new tankless water heater electric?

The electric water heaters need 240-electrical power, so it’s wise to call an electrician for routing the wiring. You may also have to install a subpanel next to your unit. It has its circuit breakers, so you may easily disconnect power to the water heater when something goes wrong.

What’s the proper way to remove the old water heaters?

More often than not, the new tankless water heater will replace an old water heater with a tank.

  • Begin with shutting off the valves on the two water lines (the inlet and outlet), going inside the current water heater. You can use a pipe wrench or channel-type pliers for loosening and disconnecting the lines.
  • Continue with opening the drain valve found at the bottom, draining the tanks. If it’s a gas unit, you also have to shut off the gas line valve, disconnecting the gas line later on.
  • Disconnect and take out one or two sections of the vent pipe
  • If the unit is electric, it’s wise to call an electrician for disconnecting the wiring. Disconnect the wires from the water heater, taking the old water heater off.

What to keep in mind when installing a tankless water heater?

Once you’ve run over the instruction (if you do it on your own), you should follow the next steps:

  • Take the unit out of the box, placing the hardware and user’s manual nearby
  • Look for the best place for the water heater. Make sure that you let the appropriate clearances around the water heater so that you follow the state and local building codes
  • Install the unit on the wall, according to the instructions in the manual. You need to make sure that the wall handles the weight of the water heater.
  • If you have a gas-fired unit, you need to install ventilation ducting. Most of the time, tankless water heaters need larger flue and even stainless steel flue
  • Start with the supply line (waterline).
  • Address the heat source. In the case of electric models, you have to plug it into the wall. For the gas models, it’s necessary to connect a gas supply line from the stub at the wall, to the new unit. Make sure that you open the valve so that the handle has the same orientation as the line.
  • Grab the user’s manual once more and check to see how to light the pilot on the gas water heater
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