Rinna water heaters are well-designed appliances. One of their benefits is they display error codes when there’s a problem that requires your attention. For example, a common code that people see is code 11, but what does it mean?

Code 11 on a Rinna tankless water heater refers to an ignition problem. A problematic ignitor, gas supply issues, faulty flame rod, blocked vents or excess moisture typically cause it. You can troubleshoot this problem yourself. However, it’s best to contact a professional if you’re not confident about checking it yourself.

This guide will walk you through the meaning of error code 11, its causes, and its troubleshooting process.

What Does The 11 Code Mean?

When your water heater shows error code 11, it’s experiencing a ‘no ignition’ condition. In other words, the appliance isn’t igniting any fuel to generate heat. Therefore, the unit isn’t producing any hot water for your household.

This error code can be pretty challenging to troubleshoot, especially if you’re doing it by yourself. That’s because there are a handful of reasons why this problem occurs.

So, read through the following section to learn what triggers the 11 code that you see on your unit.

What Causes A Rinnai Tankless Water Heater To Show Code 11?

Here are some of the causes that can trigger your water heater to display error code 11:

  • Faulty ignitor: Code 11 is an ignition problem. Therefore, one of the root causes could be a defective ignitor that no longer functions.
  • Gas supply issues: If the ignitor is in good shape, a lack of gas supply is another thing to consider. Without any gas, there’s nothing for the heater to ignite.
  • Flame rod problems: The flame rod senses whether or not there has been an ignition in the heater. If it’s faulty, it won’t detect anything even if ignition has occurred.
  • Venting issues: Blocked intake and exhaust vents can also trigger code 11 indirectly. They can lead to buildups on the flame rods that cause the code to occur.
  • Excess moisture: Lastly, excess humidity could also be to blame. A leak, for example, can cause the water heater’s electronic and electric components to corrode. That corrosion can then trigger code 11, whether or not it’s correct to do so.

How Do You Fix Code 11?

As you read earlier, there are several reasons why your tankless water heater is showing code 11. So, you’ll have to take an organized step-by-step approach to troubleshoot all possible causes and clear the code.

Tools Needed to Troubleshoot Rinnai Tankless Water Heater Error Code 11
Crescent wrench
Gas pressure gauge
Multimeter (to check for open or short circuits)
Cleaning cloth or brush (to clean the burner surface)

It’s important to have the manufacturer’s instructions or manual on hand to refer to the dip switch settings and other specifications. Additionally, make sure to wear appropriate safety gear, such as gloves and eye protection, when working with gas appliances. If you’re unsure about any of these steps or don’t have the necessary tools, it’s best to contact a professional for assistance.

When you have that together here is a step-by-step troubleshooting guide.

Note: If you’re unsure about any of these steps or don’t have the necessary tools, it’s best to contact a professional for assistance.

1. Check Gas Supply

  • Make sure the gas supply is turned on: If you’re using a gas line from your home or building, ensure that the gas supply valve is turned on. This valve is typically located near the gas meter or at the main gas line entering the building. If you’re using a propane tank, check the tank valve to make sure it’s open.
  • Check the gas meter: If you’re using a natural gas supply, check the gas meter to ensure that the needle is moving. If the needle is not moving, the gas supply may be turned off, or there may be an issue with the meter.
  • Check the cylinder or tank: If you’re using propane, check the cylinder or tank to make sure it’s not empty and that the valve is open.
  • Check the valve at the unit: Make sure that the gas supply valve at the unit, where the tankless water heater is installed, is open. This valve is typically located near the heater and will have a lever or knob that can be turned to open the valve.
  • Check the gas type: It’s important to ensure that the gas type being supplied matches what the unit is designed to use. Check the manufacturer’s instructions or specifications to determine which type of gas your unit is designed to use. If you’re unsure, consult a professional or contact the gas supplier for assistance.

2. Check Gas Pressure and Line Size

  • Gas line size: The gas line size refers to the diameter of the gas pipe that connects to the tankless water heater. The size of the gas line is important because it determines the amount of gas that can flow to the unit. The manufacturer’s instructions will provide guidance on the recommended gas line size for your specific model of tankless water heater. If the gas line is too small, it may not provide enough gas to the unit, which can cause it to operate inefficiently or not at all.
  • Gas pressure: The gas pressure refers to the force at which gas flows through the gas line to the tankless water heater. Too high or too low gas pressure can cause issues with the unit’s operation, so it’s important to ensure that it’s within the specified range. The manufacturer’s instructions will provide guidance on the recommended gas pressure range for your specific model of tankless water heater. Gas pressure can be measured using a gas pressure gauge that can be attached to a test port on the gas line.
  • Gas regulator: The gas regulator is an important component that helps control the gas pressure that is delivered to the tankless water heater. The regulator ensures that the gas pressure is within the range specified by the manufacturer. Make sure that the regulator is properly installed and that it’s the correct type for your specific model of Rinnai tankless water heater.

3. Bleed Air From Gas Lines

Bleeding air from a gas line is important to ensure that there is no blockage or buildup of air in the line that could prevent proper gas flow. Here are the steps to bleed air from a gas line:

  • Turn off the gas supply: Before you begin, make sure the gas supply to the line is turned off. This is an important safety precaution.
  • Locate the air vent: The air vent is a small valve located at the highest point in the gas line. It may be located near the gas meter or the appliance that the gas line feeds.
  • Open the air vent: Use a wrench or pliers to turn the air vent counterclockwise to open it. You should hear a hissing sound as the air begins to escape from the line. Keep the air vent open until you no longer hear any hissing sounds.
  • Close the air vent: Once all the air has been bled from the gas line, use the wrench or pliers to turn the air vent clockwise to close it. Be careful not to overtighten it.
  • Turn on the gas supply: Finally, turn on the gas supply to the line and check for proper gas flow. If you detect any gas leaks or other issues, turn off the gas supply and contact a professional to inspect the line.

Note: It is important to follow all safety precautions when working with gas lines. If you are not comfortable working with gas lines, contact a professional to perform the work for you.

4. Verify Dip Switch Settings

  • Locate the dip switches: The dip switches are small switches located on the control board of the Rinnai tankless water heater. They control various settings on the unit, such as the maximum temperature, the gas type, and the altitude.
  • Consult the manufacturer’s instructions: To make sure the dip switches are set correctly, carefully review the dip switch settings on the unit to make sure they match the recommended settings and adjust them as needed.
  • Test the unit: After verifying and adjusting the dip switch settings, test the unit to make sure it’s functioning properly.

If you go through those steps and are still getting error code 11 here are a few additional Troubleshooting steps:

  1. Check Grounding: Make sure that the Rinnai tankless water heater is properly grounded to prevent electrical problems that can affect ignition.
  2. Disconnect EZConnect or MSA Controls: If you have an EZConnect or MSA control system connected to your Rinnai unit, disconnect it temporarily to isolate the problem.
  3. Check Igniter: Check if the igniter is operational by inspecting the spark or flame. If it’s not working, you’ll need to replace it.
  4. Check Wiring Harness: Inspect the wiring harness that connects the igniter to the control board for any signs of damage. Damaged wiring can cause the unit not to ignite.
  5. Check Gas Solenoid Valves: Check the gas solenoid valves for any signs of open or short circuits. These valves control the flow of gas to the unit and can prevent ignition if they’re not working properly.
  6. Check Burner Cover and Plate: Remove the burner cover and plate to inspect the burner surface for any debris or condensation. This can affect the unit’s ability to ignite and should be cleaned if necessary.

By following these troubleshooting steps, you can potentially save yourself time and money by fixing the problem yourself. However, if you’ve gone through all of these steps and your Rinnai tankless water heater still isn’t igniting, it’s time to call a professional for help.

Overall, if you take care of your Rinnai tankless water heater with regular maintenance and troubleshoot any problems promptly, it can provide efficient and reliable hot water for years to come.