Home Error Code Fix E05 Error Code: How to Quickly Fix it

E05 Error Code: How to Quickly Fix it

by Timothy Ginn

The E05 error code on a water heater may be caused by a faulty stack flue sensor or damaged thermal regulator. Faulty stack flue sensors can often be repaired by replacing the sensor itself.

When your water heater displays the E05 error code, it indicates a problem with either the stack flue sensor or the thermal regulator. These components are crucial for proper operation and safety of the water heater. A faulty stack flue sensor can often result in the E05 error code, indicating that it needs to be replaced.

Alternatively, a damaged thermal regulator may also trigger the E05 error code. It is important to address these issues promptly to ensure the efficient and safe functioning of your water heater.

Common Causes Of E05 Error Code

The E05 error code is a common issue that occurs in various devices, such as water heaters, printers, and washing machines. This error can be frustrating, but understanding its common causes can help you troubleshoot and resolve the issue quickly.

Sooted Exchanger (Fuel Delivery, Venting)

One of the main reasons why you may encounter the E05 error code is a sooted exchanger. This can happen due to problems with fuel delivery or improper venting. When the exchanger becomes sooted, it can lead to inefficient heating or cooling, resulting in the error code. To fix this issue, you should check the fuel supply and ensure that it is clean and free from any blockages. Additionally, inspect the venting system and make sure it is properly installed and functioning correctly.

Scaled Up Exchanger (Water Side)

Another common cause of the E05 error code is a scaled up exchanger on the water side. Over time, minerals and deposits can accumulate on the exchanger, reducing its efficiency and triggering the error. To address this issue, you can descale the exchanger using a suitable descaling solution. Follow the manufacturer’s instructions and ensure proper rinsing to remove all the deposits. Regular maintenance and descaling can help prevent this issue from occurring in the future.

Incorrect Installation of Print Head

If you are experiencing the E05 error code on a printer, it could be due to the incorrect installation of the print head. The print head may not have been installed at all or might not be properly aligned. To resolve this, carefully remove the print head following the manufacturer’s instructions and reinstall it correctly. Ensure that it is firmly secured and aligned properly. This should eliminate the error and allow the printer to function as intended.

In conclusion, the E05 error code can be caused by various factors depending on the device. By addressing the common causes mentioned above, you can effectively troubleshoot and resolve the issue. Remember to refer to the device’s manual or seek professional assistance if needed.

1. Checking The Stack Flue Sensor

Overview of the Stack Flue Sensor

The stack flue sensor is an important component of your heating system that helps to ensure that it is operating safely and efficiently. It measures the temperature of the flue gases and provides feedback to the control board of your heater. This information is crucial for proper combustion and preventing any potential safety hazards. However, if you are experiencing an E05 error code, it may indicate that there is an issue with the stack flue sensor.

Testing the Stack Flue Sensor

In order to check if the stack flue sensor is functioning correctly, you can perform a simple test. Here are the steps:

  1. First, turn off the power to your heating system to ensure your safety. Locate the stack flue sensor, which is usually located near the flue pipe or air vent.
  2. Next, carefully remove the sensor from its housing. Take note of its position and orientation for reinstallation.
  3. Using a multimeter set to measure resistance, touch the probes to the terminals on the stack flue sensor. The specific resistance values may vary depending on the make and model of your heating system, so refer to your manufacturer’s manual for the correct readings.
  4. If the resistance reading falls within the acceptable range, the stack flue sensor is functioning properly. However, if the reading is outside of the specified range or shows no reading at all, it indicates a faulty sensor that needs to be replaced.

How to Remove the Stack Flue Sensor

If the test confirms that the stack flue sensor is faulty, you will need to replace it. Here is how you can safely remove the stack flue sensor:

  1. Again, ensure that power to your heating system is turned off to prevent any accidents. Locate the stack flue sensor and take note of its position.
  2. Disconnect any wires or connectors connected to the sensor. Take care not to damage the wires during the removal process.
  3. Using an appropriate tool, such as a screwdriver or wrench, carefully unscrew and remove the sensor from its housing.
  4. Once the old sensor is removed, you can now install the new stack flue sensor. Ensure that it is positioned correctly and securely in the housing.
  5. Reconnect the wires or connectors to the new sensor, making sure they are properly attached.

By following these steps, you can easily check and replace a faulty stack flue sensor, which may be the cause of the E05 error code in your heating system. However, if you are unsure or uncomfortable with performing these tasks, it is always recommended to seek professional assistance from a qualified technician.

2. Fixing The Sooted Or Scaled Exchanger

When it comes to dealing with the E05 error code on your water heater, one of the possible causes could be a sooted or scaled exchanger. This can result in inefficient heating and poor performance of your water heater. In order to fix this issue, there are two main steps you should follow: identifying and fixing fuel delivery and venting issues, and removing scale buildup from the exchanger on the water side.

Identifying and fixing fuel delivery and venting issues

The first step in fixing a sooted or scaled exchanger is to identify and address any fuel delivery and venting issues that may be present. This is important because inadequate fuel delivery or improper venting can lead to incomplete combustion and the accumulation of soot or scale on the exchanger. Here are some steps you can take to resolve these issues:

  1. Check the fuel supply: Ensure that there is an adequate supply of fuel to the water heater. This can be done by checking the fuel source, such as a propane tank or natural gas supply, and verifying that it is turned on and functioning properly.
  2. Inspect the venting system: Examine the venting system for any blockages or obstructions that could be impeding proper airflow. Make sure that the vent pipe is clean and free from debris, and that it is properly sized and installed according to the manufacturer’s instructions.
  3. Verify the air intake: Ensure that the air intake for the water heater is not blocked or restricted in any way. This can be done by checking for any obstructions, such as debris or objects, that may be hindering the flow of air into the combustion chamber.
  4. Adjust the burner settings: If the fuel delivery and venting systems are functioning properly, but the exchanger is still sooted or scaled, you may need to adjust the burner settings. Consult the manufacturer’s instructions or a professional technician to determine the correct adjustments for your specific water heater model.

Removing scale buildup from the exchanger (water side)

In addition to addressing fuel delivery and venting issues, it is important to remove any scale buildup that may have accumulated on the exchanger on the water side. Scale, which is caused by mineral deposits in the water, can reduce the efficiency of your water heater and lead to poor performance. Here are some steps you can take to remove scale buildup:

  1. Drain the water heater: Start by turning off the water supply to the heater and allowing it to cool down. Once it has cooled, attach a hose to the drain valve at the bottom of the heater and drain the water completely.
  2. Inspect the exchanger: Take a close look at the exchanger to identify any visible scale buildup. If the scale is minimal, you can try using a soft brush or cloth to gently scrub it away. However, if the scale is heavily built up, you may need to use a descaling solution specifically designed for water heaters.
  3. Apply the descaling solution: Follow the manufacturer’s instructions for the descaling solution and apply it to the exchanger. Allow the solution to sit for the recommended amount of time to dissolve the scale.
  4. Rinse the exchanger: After the descaling solution has had time to work, thoroughly rinse the exchanger with clean water to remove any remaining scale and residue. Make sure to flush the system completely to ensure that no descaling solution is left behind.
  5. Reassemble and test: Once the exchanger is clean and free from scale buildup, reassemble the water heater and restore the water supply. Test the heater to ensure that it is functioning properly and that the E05 error code is no longer appearing.

By following these steps, you can effectively fix a sooted or scaled exchanger and resolve the E05 error code on your water heater. However, if you are unsure or uncomfortable performing these repairs yourself, it is recommended to seek the assistance of a professional technician.

3. Resolving Print Head Installation Issues

When it comes to resolving E05 Error Code in your printer, one common issue that users may encounter is problems with print head installation. A misaligned or improperly installed print head can disrupt the printing process and lead to error codes. In this section, we will discuss the common issues with print head installation and provide proper installation steps to ensure a smooth printing experience.

Common issues with print head installation

  1. Misalignment: One of the common issues with print head installation is misalignment. This can occur if the print head is not inserted properly into the designated slot or if it is not seated correctly. Misalignment can lead to poor print quality and error codes.
  2. Loose installation: Another issue is a loose installation of the print head. If the print head is not securely placed in its designated position, it can cause connectivity issues with the printer and trigger error codes.
  3. Dirty contacts: Dust, dirt, or ink residue on the contacts of the print head can interfere with the connection between the print head and the printer. This can result in error codes and printing problems.

Proper installation steps for print head

To avoid print head installation issues and resolve the E05 Error Code, follow these proper installation steps:

  1. Power off the printer: Before starting the installation process, make sure to turn off the printer and unplug it from the power source. This will prevent any electrical hazards and ensure your safety.
  2. Refer to the user manual: Consult the user manual provided with your printer model for specific instructions on how to install the print head. Each printer model may have slight variations in the installation process.
  3. Clean the contacts: Use a lint-free cloth or a cotton swab dipped in isopropyl alcohol to gently clean the contacts on both the print head and the printer. This will remove any dust, dirt, or ink residue that may hinder the connectivity.
  4. Align the print head: Align the print head according to the designated slot in the printer. Make sure it is inserted straight and firmly into the slot until it clicks into place.
  5. Check for secure installation: Ensure that the print head is securely installed and properly seated. Give it a gentle wiggle to make sure it is not loose.
  6. Power on the printer: Once the print head is installed correctly, plug in the printer and power it on. Wait for the printer to initialize and run a test print to confirm if the error code has been resolved.

By following these proper installation steps, you can avoid print head installation issues and resolve the E05 Error Code in your printer. Remember to refer to your printer’s user manual for specific instructions tailored to your printer model. Proper installation ensures optimal print quality and a hassle-free printing experience.

Frequently Asked Questions For E05 Error Code

What Is A Common Cause For A E05 Error Code?

A common cause for an E05 error code is a faulty stack flue sensor or a damaged thermal regulator.

What Is The Error Code E05 On A Pentair Heater?

The error code E05 on a Pentair heater indicates a problem with the stack flue sensor, thermal regulator, or gas supply. It can be resolved by replacing the faulty stack flue sensor or addressing any issues with the thermal regulator or gas supply system.

What Is The Code E05 On A Hayward Pool Heater?

The code E05 on a Hayward pool heater indicates a faulty stack flue sensor.


To conclude, the E05 error code can have various causes, such as a faulty stack flue sensor or a damaged thermal regulator. It is important to identify the specific issue and take appropriate action. By following the troubleshooting steps provided by professionals in videos and forums, you can resolve the error and restore your appliance’s functionality.

Remember to consult a qualified technician if needed.

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