From sign-in to full control in under two minutes. Here's a step-by-step walkthrough of the entire experience.
Onsu Home currently supports internet-connected Rinnai tankless water heaters (Control-R compatible). You’ll need an existing Rinnai Control-R account. Onsu Home is an independent product and is not affiliated with any water heater manufacturer.
Visit onsuhome.com and tap the "Sign in with Google" button. We use Google Sign-In for authentication — no new account to create, no password to remember. Your Google profile picture and email are used to identify your account throughout the app.
If you'd like to explore first, a demo mode is coming soon — you'll be able to try the full interface with simulated data without signing in.
After signing in, you'll see a screen asking for your Rinnai Control-R credentials (the same email and password you use with the Rinnai app). You’ll need an existing Rinnai Control-R account with your heater already linked. If you don’t have one, download the Rinnai Control-R app, create an account, and link your heater first.
Your credentials are encrypted at rest and are never sent anywhere except to Rinnai's servers. You can unlink your Rinnai account at any time from the Account tab, which immediately deletes the stored credentials from our systems.
If your Rinnai account has multiple water heaters connected, you'll see a device selection screen listing all available heaters by model and serial number. Tap the one you want to control. On the Free and Hot tiers, you select one heater. On Blazing, you can connect up to 3 heaters with a 14-day rotation cooldown if you exceed that limit. On Molten (4–10 heaters), you can manage all your heaters and switch between them freely.
Once linked, you land on the Control tab — the main dashboard. Here's what you'll find across the five tabs:
The centerpiece is a temperature dial that shows your heater's current setpoint. Drag the dial or use the +/- buttons to adjust the temperature from 100°F to 140°F. The dial color shifts from cool blue (100°F) through indigo (120°F) to orange and red (130°F+) for quick visual feedback.
Below the dial, you'll find quick-set preset buttons for common temperatures (100°, 110°, 120°, 130°, 140°). One tap sets the temperature instantly.
The recirculation panel lets you start or stop your recirculation pump with a single button press. A timer shows how long recirculation has been running, and a counter tracks your daily usage against your tier's limit (for example, "2 of 5 used today").
Vacation mode can be toggled from this tab as well. When on, your heater enters standby — useful when you're traveling and don't need hot water.
Create recirculation schedules that run automatically. Each schedule has:
Schedules execute server-side, so they work even if your browser is closed. The Free tier allows 1 schedule that expires after 30 days. Paid tiers offer more schedules with no expiry.
You can enable, disable, edit, or delete schedules at any time. Disabled schedules stay in your list but don't execute until re-enabled.
A real-time overview of your water heater's state. The Status tab displays:
All values update in real time as your heater reports its state.
A timestamped log of every action performed through Onsu Home and every event reported by your heater. Each entry shows what happened (e.g., "Temperature changed to 120°F"), when it happened, and whether it succeeded (green dot) or failed (red dot).
The Free tier shows the last 24 hours of activity. Hot shows 48 hours. Blazing and Molten show a full 7 days. Up to 200 entries are stored at any time.
Manage your profile, subscription, and preferences. From here you can:
Create a recirculation schedule for 15 minutes before your usual wake-up time. You'll have hot water at the tap the moment you step into the shower — no waiting.
Tap a quick-set button to jump to common temperatures instantly. Lower to 110°F for handwashing, bump to 120°F for showers, or set 130°F when you need extra hot water for cleaning.
After your first scheduled recirculation, check the Activity tab to confirm it executed successfully. This helps you verify that your heater and network connection are working reliably.
For the best experience, install Onsu Home as a PWA. On iOS, tap the share icon → "Add to Home Screen." On Android, tap the browser menu → "Install app." It opens full-screen like a native app.
Head to onsuhome.com and sign in. The whole setup takes about two minutes. Or check out the FAQ if you have more questions.