How to Connect a Tankless Water Heater

Tankless water heaters can be added to sinks

Instead of wasting energy keeping a large tank of water hot, a tankless heater warms water on demand. This not only saves water and energy, but can cut utility bills. It also provides instant hot showers and tap water. A tankless hot water heater is a relatively simple device and can be installed by the handy homeowner in just a few hours.

Things You'll Need

• Tankless water heater (instant-hot unit)
• 3/4-inch copper pipe
• Solder
• Welder or propane torch
• Pipe cutter
• Duct silicone

Instructions

1. Turn off your household water main. This is typically located outside of the home, and can be shut off by turning the valve tightly to the right. Turning off the water before you begin will help prevent potential leaks.

2. Find the valve on your existing hot water heater and turn it off by twisting to the right. Connect a garden hose to the spigot at the bottom of the heater and open this valve to empty the water from the tank.

3. Remove your old hot water heater and donate or recycle it. It may be bolted to the floor or the wall, so check for fasteners before attempting removal.

4. Hang your new tankless water heater unit on the wall so that the existing vent pipe from your old heater lines up with the exhaust connection on your new unit. Connect the vent on the heater to the existing vent line. You may need to use a connecting duct section if the vent ducts are not the same size. Use a silicone duct seal to ensure a tight bond between the pieces.

5. Connect the cold water input line using copper pipe and fittings. Apply solder to all connections, and use your torch to melt the solder and secure the connections. Use caution when working with the torch, keeping it away from combustible materials. It is also advisable to wear safety glasses when working with a propane torch.

6. Attach the hot water output lines. Again, use copper pipes and fittings, soldering each connection. To ensure compliance with building codes, add a shutoff valve on this line near the water heater. This is a simple copper fitting that works just like a regular joint. It should be soldered in place as well.

7. Plug your tankless hot water heater into the wall and enjoy the instant hot water it provides.

Tips & Warnings

• If you would prefer a gas powered tankless water heater, you should hire a licensed plumber. While electric versions are fairly simple to install, working with gas can be dangerous, and is best left to a professional.

References

• Rheem Tankless Water Heaters

Resources

• The Daily Green - Tankless Water Heaters