Your Rinnai unit throws an error code, you address the underlying cause, and now you’re staring at a display that still shows the code. Many homeowners don’t realize that some codes need to be manually reset even after the actual problem is resolved.
Many Rinnai tankless water heater error codes can be cleared by power cycling the unit, turning it off at the breaker or unplugging it, waiting a short period, then restoring power, though this should only be done after the underlying issue causing the code has actually been addressed. Clearing a code without fixing the root cause typically results in the same code reappearing quickly.
Step 1: Identify and Address the Root Cause First
Before attempting to clear any error code, confirm what the code actually means for your specific unit and address that underlying issue. Clearing a code that flags a real ongoing problem, like a gas supply issue or venting blockage, without fixing it first is not a real solution and can mask an issue that needs attention.
Step 2: Power Cycle the Unit
For many Rinnai units, turning off power at the breaker (or unplugging the unit if it has a standard plug), waiting approximately 30 seconds to a minute, then restoring power will clear a resolved error code and reset the unit’s control system.
Step 3: Check for Manual Reset Procedures
Some error codes require a specific manual reset sequence rather than a simple power cycle, this varies by model and code, so check your unit’s manual for any code-specific reset instructions before assuming a power cycle alone will work.
Step 4: Confirm the Code Doesn’t Return
After clearing the code, run the unit through normal operation, drawing hot water at a typical fixture, and confirm the code doesn’t reappear. If it does, this is a strong signal the underlying issue wasn’t actually resolved and needs further attention, potentially from a licensed professional.
When Power Cycling Doesn’t Clear the Code
If a code persists after power cycling and after you’ve confirmed the underlying issue is addressed, this can indicate a deeper problem requiring professional diagnosis, such as a failing sensor or component rather than a simple triggered condition.
Codes You Shouldn’t Just Clear and Ignore
Any code related to gas supply, ignition failure, or venting should be treated as a signal to call a professional if basic homeowner checks don’t resolve it, rather than repeatedly clearing the code and hoping it doesn’t return. Persistent codes are the unit telling you something needs real attention.
For a full breakdown of what different codes mean before attempting to clear them, see our [error code guide]. For general troubleshooting steps, see our [problems and fixes guide].
Rinnai RXP199iN Condensing Tankless Water Heater with Built-In Recirculation Pump - View on Amazon
The Bottom Line
Clearing a Rinnai error code generally involves power cycling the unit after addressing the underlying cause, not before. If a code returns after clearing, that’s a sign the real issue hasn’t been resolved and may need professional attention.
Frequently Asked Questions
How do I clear an error code on my Rinnai tankless water heater? Address the underlying cause first, then power cycle the unit by turning off power at the breaker, waiting briefly, and restoring power.
Can I clear an error code without fixing the actual problem? You can, but the code will typically reappear quickly since power cycling only resets the display, it doesn’t resolve an ongoing underlying issue.
How long should I wait before restoring power during a reset? Generally about 30 seconds to a minute is sufficient for most units, though check your specific model’s manual for exact guidance.
Do all error codes clear with a simple power cycle? Most do, but some codes require a specific manual reset sequence, so check your unit’s manual for any code-specific instructions.
What does it mean if an error code keeps coming back after I clear it? This is a strong signal the underlying issue wasn’t actually resolved and likely needs further troubleshooting or professional attention.
Is it safe to keep clearing the same error code repeatedly? No, repeatedly clearing a recurring code without addressing the root cause can mask a real problem that needs attention, particularly for gas or ignition related codes.
Should I call a professional if power cycling doesn’t clear the code? Yes, this can indicate a deeper issue like a failing sensor or component that requires professional diagnosis.
Can I damage my unit by power cycling it to clear a code? No, power cycling is a standard and safe reset method when done correctly, as long as the underlying cause has genuinely been addressed first.
Where do I find the specific reset procedure for my error code? Your unit’s owner’s manual is the best source for code-specific reset procedures beyond a standard power cycle.
What should I do if I’m not sure what caused the error code? Consult your unit’s manual or Rinnai’s official documentation to identify the code’s meaning before attempting any reset.
References
- Rinnai official troubleshooting and reset documentation, accessed July 2026: https://www.rinnai.us
- Rinnai official product specifications for the RXP199iN, accessed July 2026: https://www.amazon.com/s?k=Rinnai+RXP199iN