Onsu Home is a web-based control panel for Rinnai tankless water heaters. It lets you adjust temperature, start recirculation, create schedules, and track activity — all from your browser. Think of it as a smarter, more capable remote control for your water heater.
No. Onsu Home is built and operated by The Kosh Labs LLC. It is not affiliated with, endorsed by, or sponsored by any water heater manufacturer. Onsu Home connects to your heater through the manufacturer's cloud API — the same system their own official apps use — but we are an independent third-party service.
Onsu Home offers features that the official Rinnai app doesn't: recirculation scheduling with day-of-week control, detailed activity logging with timestamps, multi-heater management from a single dashboard, tier-based feature scaling, and a modern web interface that works on any device without installing an app. It's designed to be the control center you wish your heater came with.
You need a Rinnai Control-R account with your water heater already linked. That's the same account you use with the official Rinnai app. If you don't have one yet, download the Rinnai Control-R app from the App Store or Google Play, create an account, and link your heater first. Then visit onsuhome.com, sign in with Google, and enter your Rinnai credentials. No app download required — Onsu Home runs entirely in your browser.
Onsu Home currently supports Rinnai tankless water heaters that are compatible with the Rinnai Control-R system. This includes most Rinnai models with built-in Wi-Fi connectivity, such as the RUR, RSC, and RE series with the Control-R module. If your heater works with the Rinnai Control-R app, it should work with Onsu Home.
We’re working on expanding compatibility to additional water heater brands. If you’d like to be notified when your brand is supported, reach out to hello@thekoshlabs.com.
Onsu Home lets you adjust your water heater’s temperature within the range supported by your hardware. You are responsible for following the safety guidelines published by your water heater manufacturer and your local authorities. The U.S. Consumer Product Safety Commission recommends a maximum of 120°F (49°C) to reduce the risk of scalding. Temperatures above this level may be appropriate in some circumstances, but please exercise caution — especially in homes with children, elderly residents, or anyone with reduced sensitivity to heat.
Yes. The interface is fully responsive and works on phones, tablets, and desktops. We recommend modern browsers: Chrome, Safari, Firefox, or Edge. The app is optimized for mobile-first usage — most people control their heaters from their phone.
Onsu Home requires an internet connection to communicate with your water heater through Rinnai's cloud. If your internet goes down, you won't be able to control the heater through Onsu Home. However, any schedules that are already active will continue running server-side until the connection is restored.
Go to onsuhome.com and sign in with your Google account. No separate registration is needed — your Google account is your Onsu Home account. After signing in, you'll be prompted to link your Rinnai account by entering your Rinnai Control-R credentials.
Yes. Your Rinnai credentials are encrypted at rest and are transmitted exclusively over HTTPS/TLS. We store them only to communicate with Rinnai's API on your behalf. You can unlink your Rinnai account at any time, which immediately deletes the stored credentials. See our Privacy Policy for full details.
We’re building a demo mode that will let you explore the full interface with simulated heater data — no account or Rinnai credentials needed. Stay tuned.
The Free tier is free forever and includes basic water heater control with ads. Paid tiers remove ads and unlock additional features: Hot at $2/month (or $20/year) adds more schedules, recirculations, and activity history. Blazing at $5/month (or $50/year) adds multi-heater support (up to 3) and extended history. Molten at $3/heater/month (or $30/heater/year) supports 4–10 water heaters for large homes or property managers. See the full pricing comparison.
Yes. Subscriptions are managed through Paddle, our payment processor. You can cancel at any time through the links in your Paddle receipt emails or from the Account tab in the app. After cancellation, you keep access to paid features until the end of your current billing period, then revert to the Free tier.
Yes. We offer a full refund within 7 days of any purchase or renewal. Contact billing@thekoshlabs.com or use the Manage Subscription link in your receipt email. Refunds are processed by Paddle and typically appear within 5–10 business days.
Ads help us cover server costs and continue developing Onsu Home while keeping the core experience free. Ads are served by Google AdSense and are only shown after you consent to advertising cookies. Paid tiers never see ads. You can also opt out of personalized ads through Google Ads Settings.
Onsu Home supports the full Rinnai temperature range: 100°F to 140°F (38°C to 60°C). The interface provides color-coded feedback — blue for cool, indigo for warm, orange and red for hot. For safety, we recommend keeping domestic hot water at 120°F or below to reduce scalding risk, especially in homes with children or elderly residents.
You can create recirculation schedules that run on specific days of the week at a set time and temperature. When a schedule triggers, Onsu Home tells your heater to start recirculating at the specified temperature. This is perfect for morning routines — set a schedule for 6:30 AM on weekdays and have hot water ready when you wake up.
Free tier schedules expire after 30 days and must be recreated. Paid tier schedules are permanent until you delete them.
Vacation mode is a built-in Rinnai feature that puts your heater into a low-power standby state. You can toggle it through Onsu Home's control panel. When vacation mode is on, the heater won't heat water — useful when you're away from home for extended periods to save energy.
Yes, depending on your tier. The Blazing tier supports up to 3 water heaters, and the Molten tier ($3/heater/month, for large homes and property managers) supports 4–10. You can switch between heaters from the app header or the device selection screen. On Free and Hot tiers, you’re limited to one heater.
We collect your Google account email and profile photo (for authentication), your Rinnai credentials (encrypted, for heater communication), schedules and preferences you create, and anonymous usage analytics (if you consent). We never sell your data. Full details in our Privacy Policy.
Yes. In the Account tab, you’ll find a "Delete Account" button that permanently removes all your data from our systems — account information, schedules, activity logs, and stored Rinnai credentials. Billing records held by Paddle and analytics data held by Google are subject to their respective retention policies.
We use essential cookies for authentication (Firebase Auth) and two optional categories: analytics cookies (Google Analytics 4) and advertising cookies (Google AdSense, free tier only). Optional cookies are only set after you give explicit consent. You can change your preference at any time through the Account tab.
Onsu Home sends commands through the same Rinnai cloud API that their official app uses. The heater itself has built-in safety limits — it won't exceed its rated maximum temperature regardless of what settings you send. That said, you should always follow Rinnai's safety guidelines and local plumbing codes. We recommend keeping domestic hot water at 120°F or below to minimize scalding risk.
If Onsu Home becomes temporarily unavailable, your water heater continues operating at its last known settings. The heater itself is not dependent on Onsu Home — it has its own controls and safety systems. When Onsu Home comes back online, any queued schedule executions will resume normally.
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