Rheem Rtex-18 E5 Code: What It Means and How to Fix It

Rheem rtex-18 is an electric tankless water heater that can provide hot water on demand for one or two bathrooms. It is energy-efficient, compact, and easy to install and use. However, like any other appliance, it can sometimes encounter problems and display error codes on its digital display.

One of the error codes that Rheem rtex-18 can show is e5. This code indicates that there is a problem with the water flow rate or the combustion system of the unit. This can affect the performance and safety of the water heater and prevent it from heating water properly.

But don’t worry, there are some possible causes and solutions for this error code that you can try at home. In this blog post, we will explain what Rheem rtex-18 e5 code means, what causes it, and how to fix it.

What Does Rheem Rtex-18 E5 Code Mean?

Rheem rtex-18 e5 code means that the unit has detected an excessive water flow rate or an incomplete combustion. This can happen due to several reasons, such as:

• The water pressure is too high or too low
• The water filter is clogged or dirty
• The air intake filter is clogged or dirty
• The venting system is blocked or damaged
• The heat exchanger is corroded or scaled
• The combustion fan motor is defective
• The main burner or pilot is dirty or faulty
• The gas control valve is bad

When the unit detects this error, it will stop heating water and flash e5 on its digital display.

How To Fix Rheem Rtex-18 E5 Code?

Depending on the cause of the error code e5, there are different solutions that you can try to fix it. Here are some of the most common ones:

Adjust the Water Pressure

One of the possible reasons for e5 code is that the water pressure is too high or too low for the unit to operate properly. The ideal water pressure range for Rheem rtex-18 is 25 to 80 psi (pounds per square inch).

To check and adjust the water pressure, you need to do the following:

• Turn off the power and water supply to the unit and let it cool down completely.
• Locate the water pressure regulator on your main water line and adjust it according to your installation manual or local codes.
• Turn on the water supply and check the water pressure using a pressure gauge attached to a faucet near the unit.
• If the water pressure is within the recommended range, turn on the power and test the unit.
• If the water pressure is still too high or too low, contact a licensed plumber for assistance.

Clean the Water Filter

Another possible reason for e5 code is that the water filter is clogged or dirty. The water filter is located at the inlet of the unit and prevents debris and sediment from entering and damaging the unit.

To check and clean the water filter, you need to do the following:

• Turn off the power and water supply to the unit and let it cool down completely.
• Locate the water filter on your unit and remove it by unscrewing it counterclockwise.
• Rinse it under running water and use a soft brush to remove any dirt or scale.
• Reinstall it by screwing it clockwise and make sure it is tight.
• Turn on the water supply and power and test the unit.

Clean the Air Intake Filter

Another possible reason for e5 code is that the air intake filter is clogged or dirty. The air intake filter is located at the bottom of the unit and prevents dust and debris from entering and affecting the combustion system.

To check and clean the air intake filter, you need to do the following:

• Turn off the power and gas supply to – the unit and let it cool down completely.
• Locate the air intake filter on your unit and remove it by pulling it out gently.
• Rinse it under running water and use a soft brush to remove any dust or dirt.
• Reinstall it by pushing it back in place and make sure it is secure.
• Turn on the power and gas supply and test the unit.

Inspect the Venting System

Another possible reason for e5 code is that the venting system is blocked or damaged. The venting system is composed of pipes that carry the exhaust gas from the unit to the outside. It is essential for the proper operation and safety of the unit.

To check and inspect the venting system, you need to do the following:

• Turn off the power and gas supply to the unit and let it cool down completely.
• Locate the venting system on your unit and follow it to the outside.
• Check for any signs of damage, corrosion, leaks, or obstructions in the pipes, elbows, joints, or terminations.
• Remove any debris or foreign objects that may block the airflow or cause back pressure.
• Repair or replace any damaged or faulty parts of the venting system according to your installation manual or local codes.
• Turn on the power and gas supply and test the unit.

Clean or Replace the Heat Exchanger

Another possible reason for e5 code is that the heat exchanger is corroded or scaled. The heat exchanger is the core component of the unit that transfers heat from the gas burner to the water. It can get affected by hard water, minerals, or chemicals that can reduce its efficiency and performance.

To check and clean or replace the heat exchanger, you need to do the following:

• Turn off the power and gas supply to the unit and let it cool down completely.
• Locate the heat exchanger on your unit and remove it by disconnecting its wires, hoses, and screws.
• Inspect it for any signs of corrosion, scale, cracks, or leaks.
• If it is slightly dirty, soak it in a vinegar solution for a few hours and then rinse it with water.
• If it is severely corroded or damaged, replace it with a new one of the same type and size.
• Reinstall it by reconnecting its wires, hoses, and screws and make sure they are tight.
• Turn on the power and gas supply and test the unit
  

  Replace the Combustion Fan Motor

Another possible reason for e5 code is that the combustion fan motor is defective. The combustion fan motor is responsible for providing the air needed for the combustion process. It can fail due to wear and tear, overheating, or electrical issues.

To check and replace the combustion fan motor, you need to do the following:

• Turn off the power and gas supply to the unit and let it cool down completely.
• Locate the combustion fan motor on your unit and remove it by disconnecting its wires and screws.
• Test it for continuity and resistance using a multimeter. If it shows no continuity or abnormal resistance, replace it with a new one of the same type and size.
• Reinstall it by reconnecting its wires and screws and make sure they are tight.
• Turn on the power and gas supply and test the unit.

Clean or Replace the Main Burner or Pilot

Another possible reason for e5 code is that the main burner or pilot is dirty or faulty. The main burner or pilot is responsible for igniting the gas and creating a flame in the burner system. It can get clogged by dust, dirt, or insects that can affect its operation and cause incomplete combustion.

To check and clean or replace the main burner or pilot, you need to do the following:

• Turn off the power and gas supply to the unit and let it cool down completely.
• Locate the main burner or pilot on your unit and remove it by disconnecting its wires, hoses, and screws.
• Inspect it for any signs of damage, dirt, or insects.
• If it is slightly dirty, blow it with compressed air or use a soft brush to remove any debris.
• If it is severely damaged or faulty, replace it with a new one of the same type and size.
• Reinstall it by reconnecting its wires, hoses, and screws and make sure they are tight.
• Turn on the power and gas supply and test the unit.

Replace the Gas Control Valve

Another possible reason for e5 code is that the gas control valve is bad. The gas control valve is responsible for regulating the gas flow to the burner system. It can fail due to wear and tear, corrosion, or electrical issues.

To check and replace the gas control valve, you need to do the following:

• Turn off the power and gas supply to the unit and let it cool down completely.
• Locate the gas control valve on your unit and remove it by disconnecting its wires, hoses, and screws.
• Test it for continuity and resistance using a multimeter. If it shows no continuity or abnormal resistance, replace it with a new one of the same type and size.
• Reinstall it by reconnecting its wires, hoses, and screws and make sure they are tight.
• Turn on the power and gas supply and test the unit.

How To Clear Rheem Rtex-18 E5 Code?

After you have fixed the cause of the error code e5, you need to clear it from your unit’s digital display. To do this, you need to do the following:

• Turn off all hot water faucets in your home.
• Turn off the power supply to your unit for 10 seconds.
• Turn on the power supply to your unit again.
• Check if the error code e5 has disappeared from your unit’s digital display.
• If not, repeat steps 1 to 4 until it clears.

FAQ: Rheem Rtex-18 E5 Code

Here are some frequently asked questions about Rheem rtex-18 e5 code:

Q: How do I reset my Rheem rtex-18? A: To reset your Rheem rtex-18, you need to turn off – the power supply to your unit for 10 seconds and then turn it on again. This will reset the unit and clear any error codes.

Q: How do I increase the water pressure on my Rheem rtex-18? A: To increase the water pressure on your Rheem rtex-18, you need to adjust the water pressure regulator on your main water line. You can use a screwdriver to turn the screw clockwise to increase the pressure or counterclockwise to decrease it. You should check the water pressure using a pressure gauge and make sure it is within the recommended range of 25 to 80 psi.

Q: How do I descale my Rheem rtex-18? A: To descale your Rheem rtex-18, you need to flush it with a vinegar solution at least once a year. This will remove any mineral deposits that can affect the efficiency and performance of your unit. You can use a pump, hoses, bucket, and vinegar to perform this procedure. You should follow the instructions in your installation manual or contact a licensed plumber for assistance.

Rheem Rtex-18 E5 Code: Conclusion

Rheem rtex-18 e5 code is an error code that indicates a problem with the water flow rate or the combustion system of your unit. It can be caused by various factors, such as high or low water pressure, clogged or dirty filters, blocked or damaged venting system, corroded or scaled heat exchanger, defective combustion fan motor, dirty or faulty main burner or pilot, or bad gas control valve.

To fix this error code, you need to identify and address the cause of the problem. You can try some of the solutions we have provided in this blog post or contact a licensed plumber for professional help. You also need to clear the error code from your unit’s digital display by resetting it.

We hope this blog post has helped you understand what Rheem rtex-18 e5 code means and how to fix it. If you have any questions or comments, please feel free to leave them below. We would love to hear from you. Thank you for reading!