Model 3

Tankless Electric Water Heater

The world's only water heater without heating elements.

$ 999 Regular price

This is what’s inside traditional water heaters.

For over 150 years, people have been heating water using electricity and metal heating elements. Unfortunately, these metal elements rust, scale, lose energy efficiency, and eventually fail.

Heatworks water heaters have no heating elements. Instead, we use Ohmic Array Technology to heat water directly. Endlessly. On demand.

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Get endless hot water, on-demand with the MODEL 3 tankless electric water heater by Heatworks.

With our advanced all-electric technology, the MODEL 3 is able to monitor incoming data points and make adjustments 50-60x a sec. This means we maximize energy efficiency and use less electricity to heat water.

Using graphite electrodes and electronic controls, we pass controlled electric currents through the water. This transfer of electrical energy into the water increases the thermal energy, creating heat.

With no metal heating elements to scale or fail, no maintenance is ever required. That’s why we can offer the industry's only 6-year, full-unit replacement warranty.

Take a peek inside our electric tankless water heater. No metal heating elements here.

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Get endless hot water, on-demand with the MODEL 3 tankless electric water heater by Heatworks.

Powered by our patented Ohmic Array Technology, the MODEL 3 is a smart, electric tankless water heater that provides endless hot water on-demand for houses, apartments, and points-of-use. What sets it apart from other water heaters is how it heats water — you won’t find any metal heating elements inside.

Metal heating elements are a 150-year-old technology with one fundamental flaw: the metal heating elements get very hot and the minerals found in water stick to them. This causes energy efficiency loss, hot spots, and eventually the elements will fail.

Instead, the MODEL 3 uses electronic controls to pass controlled electric currents through the water, creating endless hot water, on-demand, at the temperature you want. Because no scale forms, there is never a loss of energy efficiency. No metal heating elements to replace. No maintenance.

As with all tankless electric units, the MODEL 3 only uses power when hot water is needed. Save time, money, and energy.

Small in size. Big in installation options.

The MODEL 3 can be used in new construction or as a replacement to any gas or electric tank or tankless water heater. Add it to an existing hot water system as a booster or install the MODEL 3 closer to the point of use.

Customizable based on your home and hot water needs.

Another unique feature of the MODEL 3 is the ability to adjust it from 208-240 volts and 30 to 100 amps (6.2 to 24 kW) upon installation. The higher the amperage/power setting, the more hot water the MODEL 3 can provide. To ensure you have enough power required for your hot water needs, please use the MODEL 3 sizing calculator found lower on this page.

You'll love the MODEL 3 tankless water heater.

Save money and resources
  • No metal heating elements to scale or rust
  • Only uses power when hot water is needed
  • Maintains its energy efficiency throughout the life of the unit
  • 25-40% in energy savings each month
Offers peace of mind
  • Get endless hot water on-demand
  • Requires no annual maintenance
  • No elements to replace
  • 6-year full-unit replacement warranty
  • Customer support 7 days a week
Made for today’s smart homes
  • Wi-Fi connectivity
  • Monitor while away
  • Download Heatworks’ free mobile app to remotely control the unit and manage software updates
  • Digital display
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Technical Specs

technical specs of MODEL 3 technical specs of MODEL 3
Product Information
  • Product Information
  • Operating Ranges
35 lbs.
3/4” NPT male connections
Digital Controls
LED panel, Full Wi-Fi connectivity & mobile app
Standard Warranty
6-year full unit exchange; Optional 4-year extended warranty available
Download Specs & Sizing Guide View warranty policy View/download installation manual
208-240 V*
50/60 Hz
6.2-24 kW*
Max Inlet Temp
140° F / 60° C
Working Pressure
30-75 psi / (2.06 bar-5.17 bar) 206 kPa-517 kPa
Required Conductivity
80-2000 µS**
30-100 A*
* Note
Unlike other water heaters, the MODEL 3 can be adjusted from 208-240 volts and 30 to 100 amps (6.2 to 24 kW) upon installation, depending on your hot water needs and existing wiring limitations. The higher the amperage/power setting, the more hot water the unit can provide. Please make sure to reference both the expected temperature rise table and installation manual to make sure you have enough power required for your hot water needs before ordering.
** Note
Your water MUST be between 80 and 2000 µS for the MODEL 3 to work. Your water company can come test your water, or you can purchase a water conductivity meter that can give you a reading in as little as 5 seconds. We recommend ordering one from Amazon.

How many MODEL 3 tankless water heaters do you need?

Sizing calculator assumes your home is supplied with 240V.

Because the MODEL 3 only heats water when it is needed, it’s important to take a look at how much hot water you typically use at any given time to make sure the MODEL 3 has enough power available to heat the water in one pass. Like all tankless water heaters, the MODEL 3 can provide endless hot water when sized appropriately for a household's hot water demand. Compare this to a traditional storage tank-type water heater where it can provide hot water to a kitchen sink, dishwasher, and shower simultaneously, but only for a short period of time before turning cold. Research shows that 90% of simultaneous draws in a household are 2.12 Gallons Per Minute (GPM) or less, and up to 98% are 3.3 GPM or less.

Let’s get started.

1. Select your region for average groundwater temperature:

NORTH Average ground watertemperature is 52°F SOUTH Average ground watertemperature is 62°F EXTREME SOUTH Average ground watertemperature is 72°F EXTREME NORTH Average ground watertemperature is 42°F

2. Faucet type + quanity:

Now, determine which and how many fixtures in your home will need hot water (110°F) AT THE SAME TIME. Keep in mind the GPMs listed below are based on average flow rates in that category. The ones in your home may be different.

*Note: A bathtub faucet demand is much higher than a shower - 4 GPM and up to 8 GPM and is not an option below. Depending on the flow rate; if you live in the North or Extreme North sections of the above map, the MODEL 3 may not support this demand, even at full power (24 kW).

Choose your faucet type + quantity
  • Bathroom Faucet (1 GPM) -0+
  • Low Flow Shower (1.25 GPM) -0+
  • Kitchen Faucet (1.6 GPM) -0+
  • Shower (2 GPM) -0+


3. Results:

Based on your answers, it looks like you need a MODEL 3 @ A/240V ( kW), which requires a minimum of A electric service.

Based on your answers, it looks like you need more than 1 MODEL 3.

MODEL 3 water heaters at these kW ratings (based on Amps x Volts and assuming 240V) will fit in most homes with the electrical service listed below. That said, it is always important for the licensed electrician to calculate a load analysis for the home based on the expected MODEL 3 amperage setting rated at 40% per NEC code (NEC sections 220-82 (new buildings) or 220-83 (existing buildings)) as a non-continuous device.

Our customer support team will be able to offer more specific guidance. Feel free to contact us at 888-506-2821 or email at We are available Monday through Friday, 8:30 AM to 4:30 PM ET. On Saturday or Sunday, we can be reached by email from 9:00 AM to 6:00 PM ET.

To get a more extensive overview of temperature rises you can expect with one MODEL 3 Water Heater at different voltages, amperages, and flow rates (including bath tubs), please download the MODEL 3 Information Packet.

Refresh calculator

Control and monitor your hot water usage from anywhere.

Our WiFi-enabled mobile app allows you to remotely control the temperature of the water, monitor the amount of hot water and energy used each day in your home, and even estimate how much hot water is actually costing you. Turn the water heat down when the babysitter comes for peace of mind (or to get that teenager out of that too-long shower).

MODEL 3 app

Customer Product Reviews