When you buy directly from us, we can offer you more. 20% off our full line of optimal° tankless water heaters. No tank. No cold showers.
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
copied!
shop now, save 20%discount applied at checkout.
heat only what you use. pay for nothing you don't.
fits where tanks can't. frees up serious space.
heat exchanger, sensors, boards covered. expert US-based support.
set it from your phone. smart app on Plus models.
verified customers
best tech support I have ever seen!
"Ryan went above and beyond helping me set up my tankless water heater. I called at closing time, and he stayed to help, even using his personal phone after hours. Later, when I had error codes, he called right away and helped me fix a loose connection. Excellent service!"
quality company = quality product
"Easy installation. I had zero issues with the product during installation. This was my first time doing such a project, so that speaks for itself. Quality components, excellent customer service! You will see for yourself if you ever have to call. I am a very pleased customer."
perfect!
"I can say I am absolutely pleased as punch! Works like a champ and hooked up with no issues. And I certainly love the warranty!"
every unit delivers consistent temperature within 1°, self-diagnoses issues, and comes with a 25-year warranty.
opti plus, wifi enabled
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti plus, wifi enabled
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti plus, wifi enabled
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti plus, wifi enabled
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti, standard
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti, standard
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti, standard
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
opti, standard
Every unit already includes 5% off. Your SAVE20 code adds another 20% off on top of that at checkout.
use our sizing calculator or give us a call. We'll help you find the right optimal° unit in 5 minutes. No pressure, just answers. Use code SAVE20 for 20% off.
common questions
Endless hot water, 99.9% energy efficiency, 90% space savings, and lower energy bills. Traditional tanks constantly reheat 40-50 gallons whether you're using it or not. Tankless heats on demand. You never run out mid-shower again.
25-year warranty, heat exchanger, sensors, and control boards. Free shipping on covered replacements. Our patented ultrasonic flow sensor keeps temperature within 1 degree. No cold bursts, no guessing. And US-based support you can actually reach: call 386-OPTIMAL and talk to real people who help.
Two things determine the right unit: your incoming water temperature and how many hot water fixtures you'll run at once. If you live in a colder climate (think Midwest, Northeast, or mountains), your groundwater is colder and needs more heating power. In warmer states like Florida or Texas, the same unit handles more. A household running a shower plus a dishwasher simultaneously needs more flow rate than one running just a single shower. Use our free sizing calculator or call 386-OPTIMAL. We'll size it correctly for your zip code and home in under 2 minutes.
Both models deliver identical heating performance and come with the same 25-year warranty. The right choice comes down to your preference. The opti plus adds the full optimal° app experience: real-time energy usage, temperature control from your phone, and live diagnostics. It also means our support team can see your unit's data when you call, which makes troubleshooting dramatically faster. The standard model has manual controls on the unit and an LED screen for diagnostics. Either way, the unit heats within 1 degree and performs perfectly, with or without a wifi connection.
You'll need a 240V dedicated circuit with the right breaker size and wire gauge for your unit. Here's what each model needs: Opti12: 60A breaker, 6 AWG wire. Opti15: 80A breaker, 4 AWG wire. Opti18: 100A breaker, 3 AWG wire. Opti27: 150A breaker, 1/0 AWG wire. Check your panel before ordering to make sure you have the available capacity; older homes in particular may need an upgrade. Not sure? Call us at 386-OPTIMAL before you purchase and we'll walk you through it.
Most installs take 2-4 hours with a licensed electrician or plumber, especially if you're replacing an existing tankless. We can help you find reputable installers at fair rates. Call 386-OPTIMAL or watch our installation video to see the full process.
30-60% on water heating costs. That's $200-$400+ per year for most homes. Our units only draw power when you open a hot tap. Tanks reheat 24/7 even when you're sleeping. The math is simple.
25 years on the heat exchanger, sensors, and control boards: the parts that matter most and cost the most to replace. A small number of wear items like fuses and heating elements aren't covered, but they're inexpensive and easy to swap out yourself. Free shipping on all covered replacements. US-based support for the life of the unit. Just follow the installation instructions and you're fully covered.
Call 386-OPTIMAL (386-678-4625). We're a small US-based team of real people, no phone trees. We help you pick the right unit, find installers, troubleshoot issues, whatever you need, for the next 25 years.
want to know more?
watch how tankless works and what installation actually looks like. No surprises.
20% off. 25-year warranty. US-based support. Buy direct from optimal° and keep more in your pocket.
use code SAVE20 at checkout.