Rinnai's residential warranty is the clearest in the tankless category. Three tiers, each with separate heat-exchanger, parts, and labor coverage:
| Tier | Heat Exchanger | Parts | Labor |
|---|---|---|---|
| Sensei (RU) & Sensei RX (RX) | 15 years | 5 years | 1 year |
| Luxury Series (RL) | 12 years | 5 years | 1 year |
| Value Series (V) | 10 years | 5 years | 1 year |
| Demand Duo (CHS) | 12 years | 5 years | 1 year |
| Commercial install (any line) | 5 years | 3 years | 1 year |
Warranty lookup
You need the model number and serial number from the data plate (left side of cabinet, or on the back panel). Then:
- Online: rinnai.us / warranty section — registered units appear in the lookup tool
- Phone: 1-800-621-9419 — Rinnai America customer service. Average hold under 5 minutes
- App: the ControlR app shows the install date and warranty status for any registered unit
The serial number also encodes the manufacture date. See our Rinnai age lookup if you bought a house and inherited the water heater.
Registration
Rinnai recommends registering within 30 days of installation. Registration is not legally required for warranty validity in most states, but it locks the install date in Rinnai's system — which prevents the "no record" conversation if the heat exchanger fails years later. Register via rinnai.us, the ControlR app, or have your installer submit the warranty card.
Filing a claim
- Note the error code displayed on the controller or ControlR app
- Photograph the data plate (model + serial)
- Call 1-800-621-9419 or have your installing plumber call
- Rinnai dispatches the part to a Rinnai-trained installer; labor coverage applies only in year 1
What voids the warranty
- No annual flushing/descaling in hard-water regions (over 11 grains per gallon). Rinnai inspects the heat exchanger; if it's caked, the claim is denied.
- Installation by a non-licensed plumber in jurisdictions requiring permits
- Improper venting (mixed manufacturers, incorrect diameter, exceeded length)
- Use of LP unit on natural gas (or vice versa) without conversion kit
Compared to other brands
Rinnai's 15-year Sensei heat exchanger matches Navien NPE-A2 (15-year) and beats Rheem RTGH (12-year). The 5-year parts is in line with the category. See our brand comparisons for full breakdowns.
Bottom line
Register inside 30 days, save your installer invoice, run the annual flush, and Rinnai will honor the 15-year warranty on Sensei units. For broader context see our Rinnai lineup.