Heatworks Model 3 Tankless Water Heater Energy Saver Review



The Model 3 Water Heater by Heatworks is an Internet-connected tankless water heater which provides instant, endless hot water for houses, apartments, point-of-use applications, and certain commercial applications. Our particular application here is for use in a 480 square foot cabin. Unlike conventional tank-type water heaters, the Model 3 does not store a large volume of hot water. Instead, it heats water only as needed (On Demand) using a patented Ohmic Array Technology. This process provides the purest hot water possible while saving time, energy, and water. These units are electric and only recommended for indoor use.


Heatworks is the first and only company to develop Ohmic Array Technology which uses electronic controls and graphite electrodes to heat liquids instantly, to a precise temperature, and without energy loss over time unlike traditional heating elements.


The Model 3 is relatively simple to install, however, the manufacturer does recommend that it be installed by a licensed electrician and plumber. This will cover your installation in the event of any warranty issues.

Heatworks Model 3 Mounted

For our purposes we decided to mount the Model 3 Water Heater above the bathroom in a loft area. A 40 gallon tanked water heater was previously installed in the bathroom which was removed to provide more space. To complete the installation, the existing 14 gauge electrical wire was used for power and the previously-used 30amp breaker was upgraded to a 50amp breaker. These units operate with as low as a 30 amp breaker to as high as 100 amps. The more amps powering the Model 3 the better because it increases the flow of hot water to your appliances to meet your required temperature rise.


As illustrated in the photo above, the plumbing is very simple. All fittings are 3/4″ NPT using standard hot water heater connector hoses, plumbers’ Teflon tape, and an adjustable wrench. The manufacturer recommends that the Pressure Relief Valve included with the Model 3 remain attached. They also provide a separate Pressure Reducing Valve if needed or required. Each unit comes complete with an easy to follow installation guide. You can also follow this installation video:



The Model 3 is well worth the investment. After installation was complete and air bled from the water lines, we gave it a test run. We turned on the breaker at the main electrical panel and completed the settings on the front of the unit.

Following the Installation Video above, it was a very simple process. Once the Model 3 is powered, a green light will illuminate on the front panel. Press the green light, following the provided instructions, to set the amperage (from 30amp to 100 Amp), water temperature, and voltage (in our case it is 240 volts).

The Model 3 also operates by internet-connected WIFI. You can pair it with your smartphone to control the unit remotely.

The Model 3 does have a Flow Sensor that clicks when activating on and off. This lets you know the unit is working properly to safely provide you with the hot water you need.

After completing the installation and the steps listed above to set the Model 3 amperage, voltage, and water temperature, we turned on the hot water valve. We had instant hot water! We have used the Model 3 for weeks now and are amazed by how much we prefer it over the bulky tank heater we had been using.