Efficient Troubleshooting of Rinnai Water Heaters Using Rinnai Error Codes

Learn how to troubleshoot Rinnai water heaters effectively using the Rinnai error codes. Discover the most common problems that can occur with these heaters and find out how to fix them.

Rinnai water heaters are renowned for their advanced tankless technology in North America. They are constructed using high-quality materials, incorporate state-of-the-art features, as highlighted in this review, and utilize highly sensitive components.

One of the impressive features that accompanies every Rinnai tankless water heater is the temperature controller, allowing you to easily set the desired temperature for your hot water while also providing valuable error code information when issues arise.

In the event of most error codes, the unit will automatically shut itself off as a safety measure.

Rinnai water heaters are intelligently designed, employing a self-diagnostic tool to regularly monitor their operation. When a problem is detected, specific error codes will flash on the temperature display of models such as MC-91, MCC-91, and MC-502, while on models MC-100 and BC-100, they will appear on the clock display.

It’s important to note that today’s modern tankless water heaters, including Rinnai models, feature complex designs that require specialized knowledge and skills to repair faulty elements.

Before incurring the expenses of a service call or attempting costly repairs, consider reaching out to networx.com a reputable company that can connect you with professional plumbers and provide up to 3 FREE Quotes, saving you time and money.

Rinnai Error Codes Explained and How to Fix the Problem

The standard temperature controller, MC-91, is an integral part of Rinnai water heaters, conveniently integrated into the front panel. For outdoor models, the temperature controller is included with the purchase. Additionally, advanced temperature controllers are available for those seeking extra functionality.

If your water heater is connected to MC-91 or MCC-91, accessing the most recent error codes is a breeze. Simply press and hold the ON/OFF button for two seconds, then press the “UP” arrow. This action will display and sequentially flash the last nine Rinnai error codes.

Note: We assume that your Rinnai water heater has been professionally installed by a licensed technician. It’s important to remember that different Rinnai error codes may indicate separate issues, yet they can often be resolved using the same procedure.

Error Code 02

Problem: The water heater burner does not operate in freeze protection mode.

Solution: Call a licensed technician.

Error Code 03

Problem: When using the BC-100 temperature controller for the bath fill function, there is no water flow after a power outage. Error code 03 appears on the controller.

Solution: Turn OFF the water flow on the hot water tap, then press ON/OFF twice.

Error Code 05

Problem: Bypass Servo

Solution: Perform a simple procedure: turn off the power, then turn it back on to restart the unit. If error code 05 persists on the display, the bypass valve may be broken and should be replaced.

Error Code 10

Problem: Reduced or no air supply to the water heater, or there is an obstruction in extracting flue gases.

Solution: Ensure that the recommended Rinnai venting is used, check for any obstructions in the venting system, ensure no reduction in diameter and follow instructions for recommended lengths. Also, make sure nothing blocks the venting system or fan, meet requested clearances, and ensure correct settings of dip switch and condensation collar.

Error Code 11

Problem: The gas burner fails to ignite on Rinnai water heaters equipped with electronic ignition.

Solution: Assuming correct gas type, gas pressure, and supply, as well as proper grounding, check the igniter for sparks and inspect all wiring connections. Verify the gas burner installation, remove debris and dirt if present, and check the gas solenoid valve for short circuit.

Error Code 12

Problem: Rinnai error code 12 is usually associated with flame failure. Where is the problem if your gas water heater is working and suddenly loses the flame?

Solution: Assuming professional installation and prior functionality, check for loose wiring on the PC board, power supply, and flame rod. Clean the flame rod and burner from scale build-up and debris. Inspect the gas solenoid valve for short circuits. Ensure the venting system is unobstructed, sufficient fresh air reaches the gas combustion chamber, and correct venting of gases.

Error Code 14

Problem: Thermal fuse reacts due to excessive temperature.

Solution: Check for obstructions in the venting system or water flow system. Insufficient incoming cold water through the heat exchanger can lead to increased temperature. Inspect the combustion chamber for foreign materials or scale build-up in the heat exchanger. Look for cracks or damage on the heat exchanger. Confirm that the dip switches are properly set.

Error Code 16

Problem: Over temperature warning.

Solution: Check for obstructions in the venting system or water flow system. Insufficient incoming cold water through the heat exchanger can cause a significant temperature increase. Inspect the combustion chamber for foreign materials or scale build-up in the heat exchanger. Check the heat exchanger for any signs of damage or breaking.

Error Code 19

Problem: Electric grounding.

Solution: Check all components for electric short.

Error Code 25

Problem: Full condensate trap.

Solution: Several solutions exist for a full condensate trap, including unblocking the drain line, condensate trap, and tank, fixing or tightening the sensor wiring harness, and replacing the condensate tank with the sensor.

Error Code 31

Problem: Error on the burner sensor.

Solution: Replace the sensor if it is faulty or does not have the recommended resistance value.

Error Code 32

Problem: Faulty temperature sensor on the outgoing water line.

Solution: Check the sensor wiring for loose connections or damage, measure the resistance, and clean any scale build-up. If the issue persists, replace the sensor.

Error Code 33

Problem: Faulty heat exchanger sensor.

Solution: Before replacing the faulty sensor, try fixing any loose connections, check for incorrect resistance, and clean any scale build-up on the sensor.

Error Code 34

Problem: Faulty combustion air sensor.

Solution: If the following actions don’t yield desired results, replace the faulty sensor:

• Ensure the fan is working correctly.
• Measure the resistance of the sensor and clean it from any scale build-up.
• Fix any loose connections or damaged wiring.
• Remove any restrictions in the venting system.

Error Code 41

Problem: Freeze protection sensor in external units doesn’t work.

Solution: Fix any loose, broken, or damaged sensor wiring harness, remove obstructions, and if the sensor doesn’t provide a proper reading, replace it.

Error Code 51

Problem: Freeze protection sensor in external units doesn’t work.

Solution: Fix any loose, broken, or damaged sensor wiring harness, remove obstructions, and if the sensor doesn’t provide a proper reading, replace it.

Error Code 52

Problem: Solenoid valve problems.

Solution: Measure the resistance of the valve coil or fix any damaged or loose wiring and connections.

Error Code 57

Problem: Burner overheat bi-metal switch does not work.

Solution: Ensure the water heater is set to the correct fuel type and pressure, or if a conversion was done, it was done according to manufacturer instructions. Check the switch wiring harness for proper operation. Replace the sensor if it is faulty.

Error Code 58

Problem: Secondary (condensing) heat exchanger sensor.

Solution: Check the wiring harness for any loose, broken, or damaged connections. Perform flushing to remove scale build-up inside the heat exchanger. Take necessary steps to reduce the effects of hard water.

Error Code 61

Problem: Fan failure.

Solution: Measure the resistance of the fan motor, check for any damaged or loose wiring and connections. Ensure the fan spins freely.

Error Code 65

Problem: Problems with the water flow control valve.

Solution: Call a technician as this Rinnai error code is related to the bath fill function.

Error Code 70

Problem: PC board fault.

Solution: Check the wiring and that all dip switches are in place. Replace the electronic board if necessary.

Error Code 71

Problem: Solenoid valve problem.

Solution: Replace the electronic board.

Error Code 72

Problem: Flame sensor failure.

Solution: Ensure the flame sensor is in contact with the fire. Check for any damaged or loose connections and wiring. Use sandpaper to clean deposits on the flame rod. If the above steps don’t resolve the issue, replace the flame rod.

Error Code 73

Problem: Burner sensor problem.

Solution: Ensure there is no damage to the sensor wiring or electronic board. Replace the sensor if needed.

Error Code 79

Problem: Burner sensor problem.

Solution: Ensure there is no damage to the sensor wiring or electronic board. Replace the sensor if needed.

Error Code LC or OO

Problem: Scale build-up in the heat exchanger.

Solution: Water in North America is typically hard, leading to frequent lime and scale build-up. If the “LC” error code appears on the display, clean the deposits by flushing the heat exchanger. Otherwise, replace the heat exchanger. “LC” is the only Rinnai error code that allows the water heater to keep running.

Conclusion

While the provided Rinnai error codes can assist you in troubleshooting and resolving issues with your water heater, it’s important to note that certain error codes and problems may require the expertise of a licensed technician. Service calls and technician visits can be costly and time-consuming.

To explore more cost-effective options, consider filling out this form to receive three free quotes from local plumbers (where applicable). This allows you to compare prices and make an informed decision. Remember to prioritize your safety and consult a professional when necessary.

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