We’re Here for You!

Experience Total Home Comfort!

  • FREE no obligation estimate
  • Guaranteed 5-star satisfaction
comfort union logo | A vector illustration of a bear mechanic and his son working together.
Please enable JavaScript in your browser to complete this form.
Home»Rinnai tankless water heater troubleshooting: Quick Solutions & Understanding Error Codes

Rinnai tankless water heater troubleshooting: Quick Solutions & Understanding Error Codes

rinnai tankless water heater troubleshooting

If you’re looking for a good water heater in the market, a Rinnai hot water system is probably one of the best choices in the market based on its quality and reliable solutions. However, if your Rinnai Tankless water heater doesn’t work well after some time or even right after installation, it could have several underlying issues.

In this article, we’re discussing what those issues are and how you can troubleshoot them yourself before contacting a professional to look at your water heater.

Troubleshooting Common Issues with Rinnai Tankless Water Heaters

Electric Units:

When working with electrical units, make sure the connections are secure first. Check the circuit breaker or thermal fuse box for any blown fuses or tripped breakers to make sure the unit is receiving power. It may be required to reset or replace. After you’ve eliminated electrical problems, it’s time to check the thermostat and heating elements.

Verify the continuity of each component with a multimeter. Elements that do not show continuity must be replaced. If you can hear no click as you adjust the thermostat’s temperature setting, it could be time to get a new one. If you aren’t don’t have enough resources or knowledge to do these steps, replacing these components might be dangerous, therefore it’s best to get the help of an HVAC technician.

Gas Water Heaters:

Ensure there is a complete gas supply by checking any gas appliances in your home and making sure the gas valve is fully open and the gas lines aren’t damaged. If the pilot light goes out, you need to light it again according to the manufacturer’s instructions.

It could be time to replace the thermocouple if it fails to light or remains lighted. Inspect the gas line for any air or other impediment that may be preventing gas from flowing. If the unit is still not heating water, a professional inspection is required to rule out problems with the gas valve, ignition, or gas supply line.

Insufficient hot water is a frequent complaint and can be caused by several factors:

Demand Exceeds Supply:

If you notice that the water heater can’t handle many uses at once (like running the dishwasher and taking a shower at the same time), you might want to think about timing your use or getting a different model with a higher flow rate. This is because demand exceeds supply. While tankless water heaters are better than traditional tank water heaters, it’s still best to go for a better model with a higher capacity.

Thermostat Settings:

Make sure the thermostat is adjusted to a comfortable setting. If adjusting the thermostat doesn’t fix the problem, there could be an internal issue.

System Overload:

Indicators for Overload are available in certain Rinnair tankless water heater models. Lower the demand before resetting the unit if this is activated.

Component Malfunction:

Make sure there isn’t any scale buildup on the heat exchanger, since it can drastically cut efficiency. To dissolve mineral deposits, a vinegar solution is circulated through the unit during a descaling, which may be required.

Low pressure can detract from your system’s efficiency and your comfort:

Check for Clogs:

To begin checking for clogs, clean the aerators on the hot water faucet. Your exhaust pipe or other pipes might be sediment-clogged if this doesn’t raise the pressure. This issue could be fixed by checking and flushing the system.

Inspect the Water Lines:

Make sure that the water lines going to and from the heater are straight and unobstructed. Problems like this might reduce pressure and limit the flow of water.

Water Pressure Regulator:

Verify the settings of any pressure regulators installed in your home. Reduced water pressure might be the result of a regulator that is either broken or improperly adjusted.

Variable water temperatures can be caused by several issues:

Faulty Thermostat:

Temperature fluctuations might be the result of a faulty thermostat. This issue can be resolved by testing or even replacing the thermostat.

Mixed Water Flows:

Verify that the plumbing system does not have any cross-connections that could allow hot and cold water to mix. The failure or non-installation of check valves or a cold water isolation valve can cause this.

System Overload:

In the event of a system overload, the water temperature may drop momentarily if the heater is unable to meet the demand. Stabilizing temperature output can be achieved by reducing simultaneous usage.

Water leaks can be damaging and should be addressed promptly:

Connection Points:

Ensure that all of the connections and fittings surrounding the water heater are in good working order. Reinstall any missing seals and secure any loose connections.

Pressure Relief Valve:

When the pressure or temperature is too high, this valve releases water. A leak could mean it’s functioning properly, but if it leaks often, it could be a sign of a more serious problem with the system’s pressure or temperature.

Corrosion or Damage:

Keep an eye out for physical damage or corrosion around the heat exchanger while you inspect the device. Corrosion can cause tiny fissures that water can easily pass through. Repair or replacement of heating components may be necessary due to corrosion.

Understanding Rinnai Error Codes

Error Code 03

Power supply interruption during Bath fill (Water will not flow on power reinstatement). To reset, turn off the hot water tap and press the On/Off button twice.

Error Code 10

Air intake or exhaust blockage detected. Check for clearance issues or improper venting and ensure that venting materials and installation are correct.

Error Code 11

No ignition or no gas supply. Verify that the gas is turned on at both the gas meter and the heater. Ensure that the pilot light ignites properly, and check for blockages in the supply line.

Error Code 12

Flame Failure or low gas flow. Similar to error 11, ensure adequate gas supply and check for vent blockages.

Error Code 14

Remaining Flame Safety Device error, indicating a fault in the flame sensing mechanism. This may require professional service.

Error Code 16

Over Temperature Warning. This occurs if the unit operates at an excessively high temperature. Inspecting for low flow or blockages in the heat exchanger can address this issue.

Error Code 19

Electrical Grounding error. Check all electrical connections for proper grounding and integrity.

Error Code 21

Incorrect dip switch setting detected. Review the installation settings and ensure all dip switches are correctly set according to the unit’s specifications.

Error Code 25

There is a Neutralizer Tank Sensor Fault observed, indicating an issue with the neutralizer in the condensate system. A service call is recommended.

Error Code 32

Outgoing Water Temperature Sensor Fault. Check the sensor for damage or malfunction and replace it if necessary.

Error Code 41

Ambient Temperature Sensor Fault. Ensure the sensor is functioning correctly and replace it if defective.

Error Code 52

Gas Modulating Valve Fault. This error indicates a problem with the valve operation and often requires replacement.

Error Code 61

Combustion Fan Fault. Verify the fan’s operation and check for obstructions or failures in the fan assembly.

Error Code 65

Water Flow Control Fault, which typically involves issues with the water flow control mechanism. This error requires a service call to address properly.

Error Codes 70, 71, 72

There is a potential microprocessor Fault in the hot water heater. These codes suggest a failure in the electronic control system, requiring professional diagnostics and likely replacement of the control board.

Error Code ‘X’

Wireless water controller (when fitted) is ‘Out of Range’ due to the distance from the transceiver or an obstruction. Adjust the position of the water controller or transceiver to clear obstructions or reduce distance.

Note icon | Comfort Union

Water Heater Troubleshooting Guides

Our comprehensive troubleshooting guide offers step-by-step solutions to common issues. From heating failures to airflow problems, we've got you covered."

Why is Regular maintenance important for your Rinnai Water heater?

If you want your Rinnai tankless water heater to last as long as possible and work as efficiently as possible, you must maintain it regularly. Rinnai water heaters, like any other high-tech device, are best maintained and serviced regularly to keep them running smoothly and avoid malfunctions.

Your water heater should be inspected annually by a qualified professional. The gas connections should be checked, the venting system should be clear and working properly, the heat exchanger should be examined for corrosion or wear, and all electrical components should be securely and functionally verified.

Preventing decreased water and air flow rates and operating inefficiencies can be achieved by regularly monitoring and cleaning the water inlet and air intake filters. Filter debris can reduce efficiency and even cause overheating by making the unit work harder than it has to.

Your water heater needs your constant attention. It is important to quickly resolve any performance issues or error codes that may emerge. You can find Rinnai's website or your user manual online with a list of typical error codes for your model. Get to know them so you can easily identify and fix problems.

The severity of scaling issues is proportional to the hardness of the water you use. To remove mineral deposits that have built up inside the heat exchanger and are preventing water flow and heat transfer, descaling is done by cycling a vinegar solution through the unit.

Check to see that there are no obstructions to the venting system and that it complies with city standards. Inefficient functioning and safety problems, such as carbon monoxide poisoning, can result from improper venting.

Make sure the gas pressure is within the range specified for your model as part of your routine gas pressure check. The heater's efficiency and safety are compromised when the gas pressure is incorrect, which impacts combustion.

Expert Assistance for Rinnai Hot Water Systems

Get professional help if your Rinnai hot water system is having continuous troubles or problems of a complicated kind. Among the many HVAC products and services offered, Comfort Union distinguishes out as a trustworthy authority on hot water systems.

Your Rinnai system will continue to run at its best with the help of Comfort Union’s certified technicians, who will perform thorough maintenance checks and troubleshooting as needed. Your unique requirements will be met by their expert specialists, who offer first-rate support for everything from regular maintenance to extensive repairs and system upgrades. If you own a Rinnai system, you may put your trust in Comfort Union to maintain it.

Contact us for more details of repairs and maintenance of your water heater units or other HVAC systems.

Expert Plumbing & HVAC Services

Expert Plumbing & HVAC Services

Call: 403-399-7903

Serving with a Smile