General - Tankless Technology

How does a tankless water heater work?
  • Tankless water heaters are “on demand.” Water is NOT stored. It is heated instantaneously when a hot water faucet is turned on.
  • The technology is based on the physics of heating water. It takes a specific amount of power to heat one gallon of water by one degree.

  • A flow sensor in the tankless heater reads that hot water is on and then activates the heating elements.

  • There are different types of flow sensors in the market. The most basic can only read if there is hot water running. 

  • More advanced flow sensors can read the flow measured in gallons per minute (gpm). These sensors are typically based on spinning paddles, which often break and spin loudly.

  • Optimal is the only tankless water heater using patent-pending ultrasonic sensor technology. They are more accurate, more functional, and more reliable than traditional flow sensors.

  • Tankless water heaters also come with sensors that read the inlet and outlet temperature. This information is used along with the set temperature to determine the temperature rise. 

  • Tankless heaters use the active gallons per minute, and temperature rises to provide the power needed to heat hot water demand.
What is the installation cost of an electric tankless water heater?

All Optimal heaters can replace an existing electric tankless water heater of comparable size and, in some cases, use the same electrical and plumbing runs since Opti heaters offer a ¾” NPT inlet and outlet water connection for increased flow and is standard with any tank heater. The installation cost can vary by location and Complexity of the installation. In most cases, the national average is around $2,875. This includes the cost of the unit itself, permits, installation materials, labor fees, and removal of an old water heater

Are tankless water heaters “instantaneous”?

Optimal heaters are instantaneous directly from the heater, typically within 3 to 5 seconds of action. However, keep in mind the distance from the unit to the tap. The farther the faucet is from the heater, the longer it takes for the hot water to travel to the tap.

How efficient are electric tankless water heaters?
  • Optimal heaters are highly efficient, by 99.9%. This means almost all the unit's electricity translates into water heating, minimizing energy waste. Here's a breakdown of the efficiency:


  • No standby losses: Unlike tank heaters that constantly heat and reheat water even when unused, tankless heaters only activate when you open a hot water tap. This eliminates standby losses, significantly reducing energy consumption.
  • Demand-based heating: They only heat water when needed, matching your hot water usage patterns and minimizing energy waste.
  • Reduced carbon footprint: Their lower energy consumption contributes to a smaller carbon footprint than traditional tank heaters.
Are electric tankless water heaters accurate?

All Optimal heaters can hit a set temperature within 1 degree + or - of the desired set temperature as long as you are with the flow and power parameters of the unit capabilities.

How much can I save with an electric tankless water heater?

We estimated 30% to 60% energy savings compared to tank heaters. You can expect to save 30%–60% on your water heating costs, especially if your hot water usage is moderate, with an estimated  12 to 24-month payback period of any incremental cost going from tank to tankless, depending on the model perched.

General - Optimal Technology

How does Optimal’s unique ultrasonic flow-sensing work?
  • When it comes to Unique SMART tech, Optimal’s patent-pending ultrasonic sensor technology is the most accurate and fastest flow sensor tech in the water heating market today, and it is more functional and more reliable than traditional flow sensors. 

  • How it works: Ultrasonic water flow sensors harness sound waves! They ping high-frequency sound pulses through the pipe, measuring the time it takes for echoes to bounce back from particles or bubbles in the flowing water. By comparing travel times between upstream and downstream signals, they calculate the water's speed, and with the pipe's known diameter, they instantly reveal the flow rate!


Which model is right for me?

To size an electric tankless water heater, consider both flow rate (how much hot water you need) and temperature rise (the difference between incoming and desired water temperature). Next, estimate the highest flow rate you'll have running simultaneously (e.g., 1 sink + 1 shower), and factor in your climate's cold water temperature and desired hot water temperature to determine the required temperature rise. In most cases, 105F output temp is considered optimal, and tempers abode 105 could cause scalding or irritations of the skin. Last, add your finding  (e.g., 2.5 x 33 x 147= 12,127.5) or GPM x temp rise x 147= KW) and select a heater with enough kW output to achieve.

Below is a list of hot water faucets in the home and the gallons per minute they emit:

  • Shower head: 1.5 - 2.0 gpm
  • Bathtub: 2.5 - 3.5 gpm
  • Kitchen sink: 0.75 - 1.5 gpm
  • Hand sink:0.5 - 1.0  gpm 
What is my average incoming water temperature?


What are the installation requirements?


  • All Optimal water heaters are supplied with ¾ “ NPT male connectors. 
  • We require a minimum of 12” of  ¾” copper or flex tubing connected directly to the incoming and outgoing water connectors.
  • Note: do not solder directly to the unit in case the unit needs to be serviced. 
  • All air must be purged from the line before powering the heater.


Confirm you have sufficient space in your electrical panel.

  • Depending on your model, your heater can require anywhere from one double pole breaker up to four double pole breakers. Review the specification sheet for your specific model.

Confirm you have the correct wire size and breaker size for your specific model.

Depending on your model, your unit may require either a 240v 60 amp breaker or multiple 40 amp double pole breakers. Please review the specification sheet for your specific unit.

  • Make sure to install all electrical circuits to code or city ordinance.
  •  If you need clarification on this, please consult with a licensed contractor.
Are there any electrical upgrades needed for installation?

 Electrical or Plumbing upgrades may be necessary depending on the current installation setup. If you need more clarification, please contact our support team or a local contractor for more details.

What is the lifespan of the unit?

Optimal has built its electric tankless water heater to last, so we offer a 25-year  limited lifetime warranty. Some regular maintenance is required to prolong the life expectancy of our heaters. Depending on the hardness of water in your area, you may need to service your heart every 12 - 24 months. Some units may require water softeners or filters. For more information on maintenance, please review the maintenance guide in your installer manual.

Limited Lifetime Warranty

What is the limited lifetime warranty coverage?

Included in your out-of-the-box limited lifetime warranty are:

  • All electrical sensors, thermistors, transducers, control boards, thermostats, etc.
  • Soldered heat exchangers.
  • Ground shipping within the continental US.
  • RA (Return Authorization) - A new unit if necessary (approval required by a supervisor).

For more information, please visit our warranty page.

What's not covered in the warranty?
  • Heating elements (considered wear and tear items).

  • We offer yearly or biyearly maintenance options if needed.

  • This is due to the fact that heating elements require maintenance and it is up to the customer to ensure annual maintenance is done to prolong the life of the elements. To learn more about tasks like descaling and other helpful tips, visit our maintenance section.

  • Freeze damage: Units have a freeze protection mode, which must be active and powered.

  • Any shipping methods other than ground within the continental US.

  • Labor costs associated with the installation of new parts. We have designed the heats to be serviced if necessary easily. The only tools required are one 10# Screwdriver and one adjustable wrench or channel lock. Learn about troubleshooting tasks like descaling to keep the unit running smoothly.

Routine Maintenance

What maintenance steps can be taken to prolong the life of the heater?

Regular maintenance is essential to ensure optimal performance and durability of your Optimal water heater. We recommend two options for annual maintenance:

  • Incorporate a Calcium Filter: 
  • Install a calcium filter in line with your Optimal water heater. Replace the filter every 12 to 24 months, depending on the hardness of your water in the area. 

  • System Flush with White Vinegar
  • Conduct a system flush using white vinegar (approximately 1 or 2 gallons) for 1 hour every 6 to 12 months.

Adhering to these maintenance procedures will prolong the life of your Optimal water heater and ensure a consistent supply of energy-efficient hot water. For more details and guidance on maintenance, customers can visit our website at itsoptimal.com and consult the routine maintenance section.