Skip to product information
1 of 5


19 in stock

Opti 18+ with WiFi | Optimal 18kw Electric Tankless Water Heater |

Opti 18+ with WiFi | Optimal 18kw Electric Tankless Water Heater |

Regular price $749.99 USD
Regular price $932.89 USD Sale price $749.99 USD
Sale Sold out
Shipping calculated at checkout.

Opti 18+ with Wifi | Optimal 18kw Electric Tankless Water Heater |

Lifetime warranty!


The Opti 18kW + electric tankless water heater provides efficient, continuous on demand hot water. The Opti18 is the only water heater with patent pending ultrasonic flow sensing technology providing quiet, efficient and smart control. With advanced power modulation, built in diagnostics and wireless compatibility the Opti18 heats to within 1 degree of set temperature (+ or -). Heat up to 3.7 gallons per minute (gpm) to 105°F given an inlet water temperature of 72°F. It supports a 2-bathroom home in warm climates or acts as a point of use in colder climates. Dry-fire protection prevents premature element failure for worry-free installation. The Opti18 comes with a 25-year residential warranty and a 5-year commercial warranty. COVERS ALL COMPONENTS and GROUND SHIPPING. For more information on installation, best practices, and the warranty, please use the links below.

  • Lifetime Guarantee - 25 Year Limited Warranty. Best warranty in the category. 
  • Delivers continuous hot water for 2 showers and 1 sink used concurrently (based on a 1.5 GPM showerhead and 0.5 GPM sink faucet in southern US locations) 
  • Smart Tankless Water Heater, WIFI + App Included, and only water heater with patent pending Ultrasonic flow sensing.
  • Check the Optimal Sizing guide to see the Opti18’s flow rate capacity in your area. Sizing Calculator
  • The Opti18’s compact modern design is wall mounted and frees up closet space for extra valuable storage. 
  • Optimal products come with freeze protection, leak detection and vacation mode protection.
  • Opti model products come with advanced diagnostics, no moving parts and easily replaced heating elements. 
  • This model is wifi compatible with wifi board upgrade (available soon). Select the Opti12+ for wifi enabled model. Water heater controlled with Optimal app available on IOS and Android.

Technical Specifications


2x 8 awg wire

40-amp x 2 double pole breaker

50/60 hertz

18000 watts

75 max amp draw

220/240 volts

99.9% efficient

2- 9Kw Elements 


3/4" npt connections

0.25 gpm activation

150 max psi


16.9”h x 11.4”w x 3.5”d

Indoor Use / Wall Mounted

25-year residential warranty - See link below for complete details.

ETL Listed / UL Listed / CSA Listed


View full details

Need help Troubleshooting?

Give us a call at 754-444-1735 or talk to a live agent now.

Can I talk to a live person?

Yes, our customer service team is here to assist you live, whether through phone or our chat feature. Rest assured, our representatives are real people with extensive expertise in Ecosmart, Rheem, and Eemax units.

What are your working hours?

We are open 7 days a week, from 8am- 11pm EST. Give us a call to schedule