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save up to $124
15% OFF
on all units
use code at checkout:
TRUSTOPTIMAL
limited time offer
your water heater is the only appliance you use naked.
you should trust it. 😉
save up to $124
15% OFF
on all units
use code at checkout:
TRUSTOPTIMAL
copied!
limited time offer
💰
cut water heating costs by up to 50%
save money with on-demand heating and a reliable design
📏
90% smaller than a tank
save space with our compact design
🛁
25 year warranty
backed by expert US based support
📱
wifi control
smart app included with our plus models
choose your opti
all our units deliver consistent temperature within 1 degree, self-diagnose issues, and come with a 25-year warranty.
wifi plus models include extra features:
- Control temperature from your phone
- Real-time usage metrics
- Diagnostic notifications
- Multiple-unit management
- Remote vacation mode
- Works perfectly even without wifi
- Control temperature from your phone
- Real-time usage metrics
- Diagnostic notifications
- Multiple-unit management
- Remote vacation mode
- Works perfectly even without wifi
opti15 plus | 15kw 240v 3.0gpm wifi enabled 25-year warranty electric tankless water heater
$719.00
$619.00
save $100.00 (15% off)
not sure which unit you need?
Use our sizing calculator or give us a call. We'll help you find the perfect fit in 5 minutes.
what our customers say
the highest-rated electric tankless, with 4.9/5 stars from thousands of verified buyers
★★★★★
"Extremely impressed!!! Such an amazing product!!! It was easy to install. They also have fantastic customer service which is a major plus! We are now customers for life!"
— Sarah J.
★★★★★
"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!"
— Jesse M.
★★★★★
"We have enjoyed the instant hot water usage. I have also enjoyed gaining more space in our pantry since the new hot water heater only takes up 12 inches of wall space. We are very happy with the Optimal experience!"
— Sarah P.
frequently asked questions
why choose tankless?
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. Never run out mid-shower again.
why choose optimal?
25-year warranty. Heat exchanger, sensors, control boards, all parts. Free shipping on replacements. Patented ultrasonic flow sensor keeps temperature within 1 degree. No cold bursts. US-based support. Call 386-OPTIMAL and talk to real people who actually help.
how do I choose the right unit?
Depends on how many people live there and how many bathrooms you'll use at once. Use our free sizing calculator or call 386-OPTIMAL. We'll tell you which unit fits your home in 2 minutes.
what's the difference between wifi and non-wifi?
All our units heat within 1 degree, give you diagnostics, vacation mode, and come with a 25-year warranty. But wifi units give you an extra layer of convenience with remote control from your phone using the Optimal app. One cool thing is that when you have a Plus unit, even if you don't connect it to wifi or experience an outage, the unit will work just as great at what it's meant to do: heat water.
what are the electrical requirements?
Check you have space in your panel before ordering. Your electrician will need to install a dedicated breaker: Opti12: 208V or 240V, 60 amp breaker. Opti15: 240V, 80 amp breaker. Opti18: 240V, 100 amp breaker. Opti27: 240V, 150 amp breaker. We provide full specs for your electrician. They'll handle the rest.
how complicated is installation?
Not complicated. Most take 2-4 hours with a licensed electrician or plumber, especially if replacing an existing tankless. Some installers may not be familiar with tankless. We can help you find reputable installers who charge fair rates. Call us at 386-OPTIMAL. Watch our installation video to see the full process.
how much will I save on my electric bill?
30-60% on water heating. That's $200-$400+ per year for most homes. Our units only use power when you turn on hot water. No hot water running? No power used. Tanks reheat water 24/7 even when you're sleeping.
will it give me endless hot water?
Yes, as long as it's sized correctly. Use our calculator or call us to get the right unit. Once properly sized, you'll never run out.
what's covered in the warranty?
25 years on everything. Heat exchanger, sensors, control boards, all parts. Free shipping on replacements. Expert US-based support. Just follow the install instructions and you're covered.
what if I have questions or something goes wrong?
Call 386-OPTIMAL (386-678-4625). We're a small team based in the US. Real people, no phone trees. We help you pick the right unit, find installers, troubleshoot. Whatever you need for the next 25 years.
if you need more
why this sale?
We're on a mission to convert more homes from tank to tankless. Tankless saves space, saves money, and delivers endless hot water. But we know the industry is full of confusing information and companies that don't have your back. This sale is our way of making it easier for you to make the switch to a water heater you can actually trust.
you deserve a water heater you can trust
save 15% on all optimal units
use code at checkout:
TRUSTOPTIMAL