rheem tankless water heater code 11

By SmartHomeBit Staff •  Updated: 06/08/23 •  12 min read


Rheem Tankless Water Heater Code 11 is a common issue. It means ignition failure. Clogged vents, lack of gas, igniter or flame sensor problems, and electrical wiring or control board issues can be the cause. So, it’s smart to take action fast.

If Code 11 shows up, turn off the system and inspect it. Try to find out if anything is blocking the vent or gas supply. However, trying to fix it yourself can create risks. To stay safe, call a professional.

To prevent Code 11, do regular maintenance on the system. Clean the vents, check the gas supply, and check the wiring and control board. Also, make sure the system is installed properly. Doing these things can help your tankless water heater run without any issues.

Rheem tankless water heater error code 11

Rheem tankless water heaters have modern features. But, they can experience errors, like code 11. This code means the ignition system has a problem. It could be a clogged igniter, gas valve, wiring, or control board. Check the user manual for steps to fix it.

If the steps don’t work, get help from a plumber or HVAC expert. Don’t try to fix it without knowledge as it could make the problem worse and dangerous.

In short, code 11 on a Rheem tankless water heater is an ignition system issue. Follow the steps or get professional help to fix it. Doing this keeps the unit working well, and the household safe.

Common cause of error code 11: Insufficient power supply

Error code 11 is a common issue among Rheem tankless water heaters. It’s a safety feature which stops the unit from being damaged. Low voltage, loose wiring, or a tripped breaker in the electrical supply may be the cause.

To identify and fix the issue, check the unit’s power supply voltage, wiring connections, and circuit breaker. Professional help is recommended for safety and to avoid further damage. Voltage must be appropriate for the unit to work right. Also, look at the electrical panel and the unit’s wiring connections.

If the issue persists, it may be due to a faulty control board or a malfunctioning component. Contact a service agent to replace the faulty component, ensuring smooth operation.

According to customer support, regular maintenance and proper installation can help prevent these errors. An insufficient power supply is often the cause of error code 11, so it’s best to seek professional assistance.

Troubleshooting steps for error code 11

When it comes to error code 11 in Rheem Tankless Water Heaters, finding the right troubleshooting steps is crucial. In this section, we will explore the various troubleshooting steps to fix this error code. From checking gas supply and grounding to inspecting gas solenoid valves and wiring, we will cover everything you need to know to get your Rheem Tankless Water Heater back up and running.

Checking gas supply, grounding, gas type/pressure, and bleed gas lines

This part of the article talks about fixing error code 11 on a Rheem tankless water heater. This code usually means there is not enough power. It could be due to gas supply, grounding, gas type/pressure, or bleed gas lines not working right. To check these components, do these steps:

  1. Turn off the water heater and unplug it.
  2. Look for leaks in the gas lines. If you find any, fix them.
  3. Make sure the gas supply valve is open and there is enough fuel.
  4. Check that the appliance is grounded correctly.
  5. Confirm you are using the right fuel type and pressure.
  6. Open a nearby faucet to get rid of air.

Other things can also cause error code 11. These could be main burners, gas control assemblies, or circuit boards not working correctly. If the steps above don’t help, get help from an expert who knows about Rheem products. They can suggest more advanced troubleshooting.

Also, consider that gas interruptions can trigger fault codes in some areas, based on maintenance schedules from utility companies. When working with combustible fuels, take precautions and follow safety procedures. Ask your local utility company for help if you have questions about potential hazards. Test gas flow and your Rheem tankless water heater’s gas tank often to be safe.

Testing gas flow and checking gas tank

Testing gas flow and checking gas tank is key to efficient Rheem tankless water heater operation. Here’s how to do it:

  1. Close the hot water tap and turn off the power supply.
  2. Disconnect the gas pipe from the heater’s outlet pressure tap.
  3. Connect a manometer to the end of the disconnected pipe. Turn on the tap slowly and check for consistent pressure.

If you aren’t comfortable or trained to do this, get help from a plumber. If testing gas flow and checking gas tank doesn’t resolve the error code 11 issue, have a certified technician inspect other possible causes.

If you need to investigate further and inspect gas solenoid valves and igniter wiring, testing gas flow and checking gas tank is a great first step.

Inspecting gas solenoid valves and igniter wiring

If you want to keep your Rheem tankless water heater working correctly, you need to inspect the gas solenoid valves and igniter wiring often. Firstly, turn off the gas supply and unplug the heater. Then, remove the front panel. After that, locate the solenoid valves and check they are securely connected to the igniter wiring.

Beware! If there’s any damage or corrosion, you must replace the parts right away. This can disturb the ignition sequence of your heater, causing error code 11. Also, both gas pressure and low power supply can damage the solenoid valves and igniter wiring. So, it’s best to call in an expert to prevent any further harm.

Recently, there have been more complaints about Rheem tankless water heater error code 11. To help, the manufacturer has released updated maintenance manuals. Plus, they suggest certified technicians to take care of these issues better. By inspecting the gas solenoid valves and igniter wiring regularly, you can stop and quickly solve the error code, and make sure your heater works as expected.

Resetting water heater and replacing faulty parts

Reset your Rheem tankless water heater and replace any faulty parts by following these steps:

  1. First, switch off the power and gas valve.
  2. Take off the cover panel to get access to the internal components.
  3. Look for any damage or wear, such as solenoid valves, igniter wiring, main burner, gas control assembly and circuit board.
  4. If a part looks faulty, change it with an identical one. Remember to check all components before replacing any, and get replacements from certified dealers to make sure they are compatible.
  5. After changing parts, reset your water heater by switching on the gas valve and power supply.
  6. If you still get error code 11, more troubleshooting or repair may be required.

Code 11 is just one way your tankless water heater can show you who’s boss.

Other possible reasons for error code 11

There are a few other reasons why your Rheem tankless water heater might be displaying error code 11 instead of heating up your water. In this section, we’ll explore what might be causing this error, including issues with the main burner, gas control assembly, and circuit board. If you’re experiencing this frustrating error message, keep reading to learn more about what could be wrong with your tankless water heater.

Defective main burner

A Rheem tankless water heater requires a functioning main burner to operate effectively. Error code 11 is a sign of insufficient gas supply for ignition. Common causes of a malfunctioning main burner are corrosion, wear and tear, faulty gas lines, and contaminants blocking small openings in the jets.

To fix this issue, try cleaning the burner first. Check and repair any faulty wiring, and replace malfunctioning components. If all else fails, contact a plumber. With these steps, you can take charge and get your water heater up and running again.

Defective gas control assembly

The Rheem tankless water heater might display error code 11. This is usually caused by a faulty gas control assembly. It’s an essential part of the system, responsible for controlling gas flow. When it’s damaged, the water heater may not work properly and show error codes.

Also, a defective gas control assembly can produce an irregular flame. This can harm other components, and even create dangerous gases. So, it’s important to identify and take care of any problems. Otherwise, more serious issues may occur, leading to costly repairs or replacements.

If your Rheem tankless water heater is showing error code 11 or any similar codes, it’s likely the gas control assembly is defective. Don’t let the circuit board stop functioning and get help from a professional technician.

Defective circuit board

Error code 11 may signal a defective circuit board in a Rheem tankless water heater. This board, which controls the unit, could malfunction or fail due to power surges, lack of maintenance, or incorrect connections.

Resetting the water heater and replacing parts may help. But, if the problem persists, a defective circuit board may be the cause. Some users have experienced this issue even after replacing pressure switches and gas control valves. They required a circuit board replacement at extra cost.

It’s important to monitor your tankless water heater regularly and get professional advice if you think a faulty circuit board is causing error code 11.

Gas interruptions and contacting local utility gas company

Gas interruptions with your Rheem tankless water heater? Contact your local utility gas company right away! Changes in gas pressure or supply issues can cause this. A technician can help identify and address the problem.

Don’t try to fix it yourself. It can be dangerous! The gas company techs are qualified to assess any potential gas supply problems. They can also help fix code 11 errors on your Rheem tankless water heater.

Remember, if gas supply to your furnace is stopped, other gas appliances in your home will be affected. So, regular maintenance and quick intervention by gas company technicians is needed to keep your gas system running well. If you have gas interruptions, contact your local utility gas company immediately for their help.


Frustrated with the Rheem Tankless Water Heater Code 11? Don’t worry! We know how to help. The Code 11 error indicates an ignition issue. It could be due to gas supply, air supply, exhaust vent blockages, or a malfunctioning heating element. Check the manufacturer’s manual or contact a repair technician to find the root cause. Also, regular maintenance is key. Clean air supply and exhaust vents, check gas supply lines for leaks, and monitor water flow and temperature. This will help prevent the Code 11 error and extend the lifespan of your unit. In short, Code 11 errors are stressful but with knowledge and proper care, you can avoid costly repairs.

FAQs about Rheem Tankless Water Heater Code 11

What does Rheem tankless water heater displaying error code 11 mean?

Rheem tankless water heater displaying error code 11 means that there is insufficient power supply to the unit. This can be caused by a tripped circuit breaker or a loose wire.

What are the possible causes of Rheem tankless water heater error code 11?

The possible causes of Rheem tankless water heater error code 11 include insufficient power supply, restricted gas flow, defective gas solenoid valves, damaged igniter wiring, defective main burner, and defective gas control assembly.

How can I troubleshoot Rheem tankless water heater error code 11?

To troubleshoot Rheem tankless water heater error code 11, you should check the gas supply, grounding, gas type/pressure, and bleed gas lines. You should also check the circuit board, igniter coil, and gas control assembly. If in doubt, consult a professional technician.

What solutions are available for Rheem tankless water heater error code 11?

The solutions available for Rheem tankless water heater error code 11 include replacing the gas valve, ensuring sufficient gas levels in the tank, replacing the igniter coil, replacing the circuit board, replacing the main burner, and replacing the gas control assembly.

What should I do if I suspect a gas interruption?

If you suspect a gas interruption, you should contact your local utility gas company for assistance.

How can I measure voltage across Rheem tankless water heater unit?

You can measure voltage across Rheem tankless water heater unit using a multimeter. Set the multimeter to the normal range for your voltage and then touch the probes to the appropriate contacts on the unit.

SmartHomeBit Staff