Rinnai Tankless Water Heater Error Codes: Complete Guide for RU and V Series
Quick Answer
Rinnai tankless water heaters display numeric error codes when a fault is detected. Most codes require finding the root cause before resetting.
Most codes require finding the root cause before resetting. A soft reset is done by pressing the power button twice; a hard reset by cutting power for 30 seconds.
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About These Rinnai Waterheater Error Codes
Complete reference for all Rinnai RU and V series tankless water heater error codes, including causes, diagnostic steps, and repair difficulty for each fault.
Most Common Error Codes
Dirty or failing flame rod (codes 11, 12, 15)40%
Gas supply off or low pressure (codes 10, 11, 17)24%
Combustion fan failure or blockage (codes 63, 61)14%
Venting restriction or backpressure (codes 55, 12)12%
Scale buildup on heat exchanger (codes 14, 32)10%
Symptoms You May Notice
- Numeric error code on controller display
- No hot water despite demand
- Unit fires then shuts off mid-cycle
- Clicking ignition sounds with no flame
- Exhaust smell near vent termination cap
Tools Required for Diagnosis
Flashlight (for vent inspection)Multimeter (for electrical and sensor testing)Screwdriver setManometer (for gas pressure testing)
How to Identify Your Error Code
1
Note the exact numeric code displayed on the Rinnai controller
Note the exact numeric code displayed on the Rinnai controller. Write it down so you can reference the specific code article below.
2
Check that the gas supply valve to the unit is fully open
3
Inspect the vent termination cap on the exterior of the building
4
Attempt a soft reset
5
If soft reset fails, perform a hard reset by cutting power at
Frequently Asked Questions
How do I read the error code on my Rinnai water heater?
The error code appears directly on the digital controller display as a number (e.g., 11, 63, 32). Unlike some brands, Rinnai uses plain numerics with no letter prefix. If the display is flashing, note the number being shown. To view stored error history, press and hold the Priority button for 5 seconds.
Can I reset a Rinnai error code without fixing the problem first?
You can clear the code with a reset, but it will return almost immediately if the fault is still present. The only exception is a transient fault caused by a brief gas interruption or power fluctuation, where restoring normal conditions followed by a reset is appropriate. Repeated resets without repair can mask a worsening component failure.
What are the most common Rinnai error codes?
Code 11 (no ignition) is the single most reported Rinnai fault, especially on units over 5 years old when the flame rod develops oxide coating. Code 12 (flame failure during operation) and Code 10 (no gas) are the next most frequent. Codes 63 and 61 (combustion fan faults) are common in older units or those installed in dusty environments.
Do all Rinnai RU and V series models use the same error codes?
Yes, the core numeric error code set is consistent across the RU and V series. Models like the RUR98iN (condensing) and V65iN (non-condensing) share the same codes, though some codes only appear on models with specific features, such as Code 25 which only appears on units with built-in recirculation or bath fill capability.
When should I call a technician for a Rinnai error code?
Call a licensed plumber or gas technician if the fault involves gas valve replacement (codes 10, 17, 52), PCB diagnosis, heat exchanger descaling or replacement (code 14), or if the same code returns within 24 hours of repair. Any repair involving gas lines must be leak-checked with proper equipment.
Related Rinnai Waterheater Error Codes
Code: 11Rinnai Code 11: No Ignition Fix for RU and V Series Tankless HeatersCode: 12Rinnai Code 12: Flame Failure During OperationCode: 10Rinnai Code 10: No Gas Supply or Gas Valve FailureCode: 63Rinnai Code 63: Combustion Fan ErrorCode: 17Rinnai Code 17: Gas Valve AbnormalityCode: 61Rinnai Code 61: Combustion Fan Motor FailureCode: 14Rinnai Code 14: Thermal Fuse Blown on Heat ExchangerCode: 55Rinnai Code 55: Combustion Abnormality DetectedCode: NO-HOT-WATERRinnai Tankless Water Heater No Hot Water: 6 Causes and FixesCode: 79Rinnai Code 79: Combustion Air Temperature Sensor FaultCode: 15Rinnai Code 15: Burner Ignition LockoutCode: RESETHow to Reset a Rinnai Tankless Water Heater: All Models GuideCode: 52Rinnai Code 52: Modulating Gas Valve ErrorCode: 25Rinnai Code 25: Bath Fill Error (ThermaCirc Models)Code: 32Rinnai Code 32: Outlet Water Temperature Too High
Same Fix on Other Brands
Models Known to Experience HUB Errors
This repair applies to most Rinnai waterheaters with this error code. Common model numbers include:
RUR98iN, RU199iN, RU98eN, V65iN, RL75iN, RU160iP
Last verified for technical accuracy on March 14, 2026