Turn your water heater into a hot-water battery
Make your water heater smart — so you don’t overpay
Most homes save hundreds per year.
✅ Easy install, no plumber needed
✅ Always hot water
One of the few parts of your electric bill you can control.
Your water heater is costing you more than it should
Most homes overpay for hot water — because it runs during expensive hours.
Most homes spend $400–$700 per year on electric water heating — and it’s increasing
The second largest expense on your utility bill
What’s going wrong today
📈💸 Heats during peak prices
🔥⏳ Wastes energy when no one is using hot water
🌞❌ Misses cheaper, cleaner energy
ThermoSave fixes all three — automatically.
How it Works
Avoid expensive peak electricity
ThermoSave dynamically adjusts when your water heater runs, preventing costly heating as prices and usage change.
Store energy as hot water
Your water heater holds heat, so it doesn’t need to run constantly.
Use hot water as needed
Enjoy hot showers anytime — without changing your habits.
A typical electric water heater already stores ~10 kWh of energy as hot water.
Works with standard electric resistance tank water heaters (no plumbing required).
Easy installation
Install it yourself or have a local electrician help. No plumbing required.
1. Access the heater’s electrical connections
2. Mount ThermoSave and connect the wires
3. Finish setup and control it from the app
A straightforward retrofit for existing electric tank water heaters.
See and control your hot-water battery
Track hot-water availability, heating power, and electricity prices — and see why ThermoSave heats when it does.
Preview of the ThermoSave app (features and UI will evolve).
🔍 Always know why it’s heating
ThermoSave shows when heating happens, how much power is used, and which price signal triggered it.
🔋 Hot water as a battery
Available hot water is shown as a charge level — so you instantly know if you’re ready for showers, dishes, or guests.
🧩 Works with your energy stack
Integrates with Home Assistant for live data, automations, and user-defined constraints.
✈️ Away mode (vacations & rentals)
Turn off water heating when you’re away, and have hot water ready when you’re back — no wasted energy.
Built for people who want visibility, not guesses.
See if ThermoSave makes sense for you
Most homes save hundreds per year
See a quick estimate for yours.
Great for vacations, second homes, and rentals
Just like a smart thermostat, but for hot water.
Learn how Vacation Mode works →
Get launch updates — no spam.
Join Early Access
Easy installation
Install it yourself in under 30 minutes, or have a local electrician help if you prefer.
Automatic optimization
Uses your electricity pricing, learns your hot-water usage, and schedules heating when energy is cheapest — without manual setup.
Ongoing savings
Save without changing your habits, or follow simple suggestions to save even more. Many households save up to $1,000 or more over 5 years. Estimate your savings.
Lock in Early Access pricing: $139 (future retail price $179)
Be among the first ThermoSave customers
Help shape ThermoSave — we'll follow up to hear how it goes
$19 refundable deposit applied toward final purchase
Cancel anytime before shipping for a full refund
Early Access quantities are limited
Estimated first shipments: Q2 2026
Who we are
ThermoSave is designed and tested in real homes — including our own.
We're a small team of engineers and product builders with decades of experience designing, shipping, and operating connected hardware used in homes and businesses today.
Our backgrounds span embedded systems, large-scale device fleets, cloud-connected products, and home energy — including systems that manage millions of devices in the field. We're starting anew with water heating because it’s one of the biggest, least visible energy costs in electrified homes, and one of the easiest to improve without changing how people live.
Stay in the loop
We’re building ThermoSave in the open. Get updates on testing, production progress, and launch timing.
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Used in real homes
— Havard, family of 5
— Rudi, homeowner