How To Fix Rinnai Error Code 10: Repair Tips

If you’re wondering how to fix Rinnai error code 10, this guide will help you resolve the issue. This error occurs when there’s a blockage or restriction in the air supply or exhaust system, disrupting normal airflow or flue gas extraction in your tankless water heater. While Rinnai units are highly reliable, tankless problems like this can still arise and need prompt attention.

Repairing Rinnai error code 10 successfully involves identifying the root cause, which could include venting obstructions, condensate buildup, sensor malfunctions, or incorrect gas pressure.

Below, we’ll break down the common causes, troubleshooting steps, and solutions to get your water heater back to optimal performance.

Troubleshooting Rinnai Error Code 10: Common Causes and Solutions

Rinnai error code 10 can occur due to several reasons:

• Venting system obstruction
• Incorrect venting installation
• Use of non-spec venting materials, lengths, or clearances
• Contaminants inside the venting system
• Defective sensor
• Incorrect dip switch position
• Blocked or malfunctioning fan blower
• Stuck check valve
• Condensate buildup or clogged line
• Incorrect gas pressure
• Inaccurate high-altitude setting
• Issues with the PC board

Tip: Before attempting repairs or replacing parts, try restarting the unit by turning it off and on. This simple step may resolve the issue. If the problem persists, follow the troubleshooting steps below or contact a professional plumber or technician.

Related: How to fix Rinnai error code 11

Venting Problems

Always use Rinnai-approved venting materials and accessories designed for your specific model. While aftermarket parts are widely available, they may not meet the required specifications.

Error code 10 often appears if:

• The wrong venting material is used.
• Venting elements are improperly connected.
• The venting system is incorrectly sized.
• Something is blocking the air intake or exhaust.

How to Check if the Venting System is Causing Error Code 10:

1. Remove the exhaust pipe located at the top of the water heater.
2. Turn the unit on. If the error persists, the issue is not with the venting system.
3. Disassemble all connections, inspect for damage (such as dents or changes in diameter), and remove any dirt or debris.
4. Reassemble the system according to the manufacturer’s instructions. Ensure the correct venting type is used, the number of elbows does not exceed the limit, and proper clearances are maintained.

Note: Removing the vents is only a temporary measure for testing. Always reinstall them to safely direct flue gases outdoors and ensure uninterrupted air intake. For optimal performance, inspect the venting system at least once a year.

Condensate Drainage Issues

A full condensate trap or clogged condensate line can trigger error code 10. Blockages may occur due to dirt, freezing, or damage to the line. Check the condensate collar to ensure it is properly installed and secure.

Malfunctioning Fan Blower

To inspect the fan blower:

1. Turn off the power to the water heater.
2. Check the fan housing, wheel, motor, and wiring harness for obstructions or damage.
3. Clean the fan assembly to remove any contaminants.

Dirty Air Filter (Indoor Models Only)

For indoor models, ensure the internal air filter is free of debris, lint, and dirt. Clean it using dish soap and a soft brush. Regularly inspect the air filter as recommended by Rinnai. You can find the air filter in the upper/right-hand corner of the unit after removing the front panel.

Dirty Burner Assembly

Follow Rinnai’s instructions to remove the heat exchanger and gas burner assembly. Clean all components (heat exchanger, copper fins, gas burner, and orifice) to remove debris, dirt, carbon deposits, mineral buildup, or insects. Ensure no blockages restrict airflow.

Incorrect DIP Switch Position

Verify that the high-altitude parameter settings (DIP switch) are correctly configured for your location. The PC board allows adjustments for altitudes up to 10,200 feet. Additionally, ensure the DIP switch is set correctly for the chosen vent length.

Incorrect Gas Pressure

The gas manifold’s low and high fire pressures must be set according to the manufacturer’s specifications. Incorrect pressure settings can prevent the sensor from detecting temperature changes accurately.

Important Safety Notes

• Always hire a licensed professional to service or repair your Rinnai tankless water heater.
• If attempting repairs yourself, turn off the gas, water, and electrical supply before starting.

How to Display Diagnostic Codes

If you’re troubleshooting Rinnai error codes, including this one, knowing how to access and interpret diagnostic codes is essential. Here’s how to display them:

1. Turn off the water heater.
2. Press and hold the ON/OFF button for a few seconds, then press the UP button simultaneously.
3. The last nine error codes will appear on the display.
4. To return to the previous menu, press and hold the ON/OFF button and press the UP button again.
5. Turn the power back on by pressing the ON/OFF button.

Related: Troubleshooting Rinnai error code 12

Conclusion

As we’ve seen, Rinnai error code 10 can appear on your tankless water heater for a variety of reasons. While some causes, such as cleaning the air filter or inspecting the venting system, can be resolved without professional help, others require advanced knowledge and specialized tools.

Attempting complex repairs without the necessary expertise can lead to further complications, void your warranty, or even pose safety risks. If you’re unsure how to fix Rinnai error code 10, it’s always best to contact a licensed technician to ensure the issue is resolved safely and effectively.