Rinnai tankless water heaters show a 2-digit code on the remote or LED display when something stops them from heating. Most codes point to gas supply, venting, or a dirty flame rod — not a broken unit. Find your code below for the fastest fix.
This table covers the Rinnai codes we see most often in real searches and forum threads. Codes with a link have a full walkthrough with photos and part numbers; the rest are listed here with what’s known so far and will get their own page as we film the repair.
Codes at a Glance
| Code | Meaning | |
|---|---|---|
| 10 | Air supply or exhaust blockage | Full guide → |
| 11 | No ignition — burner never lit | Full guide → |
| 12 | Flame failure — lit, then lost signal | Full guide → |
| 14 | Thermal fuse tripped (overheat protection) | Full guide → |
| LC | Scale buildup in the heat exchanger | Full guide → |
| 61 | Combustion fan failure | Full guide → |
| 63 | Fan speed / fan feedback fault | Guide coming soon |
| 79 | Water leak detected inside the unit | Full guide → |
FAQ
How do I clear a Rinnai error code?
Most codes clear on their own once the cause is fixed. If not, turn the unit off at the isolation switch or breaker for 60 seconds, then back on. If the same code returns immediately, don’t keep cycling power — move to the diagnosis steps for that specific code.
Should I call a plumber for a Rinnai error code?
Anything involving the gas valve, gas pressure, or venting should go to a licensed technician. Cleaning the flame rod, checking the isolation valve, and basic resets are safe for most homeowners.
What is the most common Rinnai error code?
Codes 11 (no ignition) and 12 (flame failure) are the two we see referenced most, usually tied to gas supply issues or a dirty flame rod.
Written by HotWater Decoded — water heater repair specialists. Technically reviewed by a licensed technician on our team.
- Rinnai diagnostic bulletins referenced across JustAnswer and repair forums
- Owner reports on r/Plumbing and heatinghelp.com
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