Disclaimer
The Potterton E28 error is a critical boiler error code that indicates a malfunction with the flue gas thermistor in your heating system. This error often points to issues that could potentially compromise the safety and efficiency of your boiler. Understanding Potterton boiler error codes and knowing how to diagnose and fix them is crucial for maintaining a safe and warm home.
What is the Potterton E28 Error Code?
The Potterton E28 error code signals a problem with the flue gas thermistor, a sensor that measures the temperature of gases exiting your boiler. This sensor operates based on the Negative Temperature Coefficient (NTC) principle, meaning its resistance decreases as the temperature increases. If this thermistor fails or malfunctions, it can lead to inaccurate temperature readings, potentially causing the boiler to shut down as a safety measure to prevent overheating.
Common Causes of the Potterton E28 Error Code
Understanding the common causes of the Potterton E28 error can help in diagnosing and resolving the issue promptly.
Flue Gas Thermistor Fault
The most direct cause of the Potterton E28 error is a sensor fault within the flue gas thermistor. Over time, the thermistor may degrade or become damaged due to factors such as exposure to extreme temperatures or wear and tear, leading to faulty temperature readings. When the flue thermostat sensor trips due to these inaccuracies, it triggers the E28 error code.
Wiring Faults
A wiring fault related to the flue gas thermistor is another common cause of the E28 error. Loose, corroded, or damaged wires can disrupt the connection between the thermistor and the printed circuit board (PCB), resulting in erroneous readings. Ensuring that all connections are secure and the wiring is intact is essential for the proper operation of the thermistor.
Issues with the Printed Circuit Board (PCB)
The PCB is the central control unit of your boiler, responsible for processing signals from various sensors, including the flue gas thermistor. If the PCB is faulty or if there is a problem with its connections, it may not correctly interpret the signals from the thermistor, leading to the Potterton E28 error. Inspecting the PCB for signs of damage, such as burn marks or loose connections, is crucial.
Gas Supply and Valve Issues
Problems with the gas supply or gas valve can also lead to the Potterton E28 error. If the gas supply is interrupted or if the gas valve fails to open or close properly, it can cause the boiler to operate inefficiently, potentially triggering a range of boiler error codes. Ensuring the gas supply is steady and the gas valve is functioning correctly is vital for avoiding these issues.
System Pressure and Flow Switch Errors
System pressure plays a critical role in the proper functioning of your boiler. If the primary system water pressure is too low or if there’s a blockage in the system, it can cause a heating flow switch error. This error, combined with issues like a probable pump jammed situation, can lead to an E28 error code. Regularly checking the system pressure and ensuring there are no blockages or leaks is essential.
Troubleshooting and Resolving the Potterton E28 Error
To effectively troubleshoot and resolve the Potterton E28 error, follow these steps:
Step 1: Inspect the Flue Gas Thermistor
Begin by examining the flue gas thermistor for any visible signs of damage or wear. Ensure that the sensor is clean, properly connected, and free from corrosion. If the thermistor appears damaged, it should be replaced with a compatible part to restore accurate temperature monitoring.
Step 2: Check Wiring and Connections
Next, inspect all wiring associated with the flue gas thermistor. Look for any loose, frayed, or corroded wires that could be causing a possible wiring fault. Secure any loose connections and replace damaged wires as needed to restore proper communication between the thermistor and the PCB.
Step 3: Examine the Printed Circuit Board (PCB)
If the thermistor and wiring are in good condition, the issue may lie with the PCB. Check the PCB for any signs of damage, such as burn marks or faulty connections. If problems are detected, the PCB may need to be repaired or replaced by a qualified technician.
Step 4: Assess Gas Supply and Valve
Inspect the gas supply and gas valve for any blockages or malfunctions. Ensure that the gas pressure is within the recommended limits and that the valve operates correctly. Any irregularities in the gas supply should be addressed immediately to prevent further issues.
Step 5: Reset the Boiler
After addressing potential causes, attempt to reset the boiler to see if the error clears. If the Potterton E28 error persists, it may indicate a deeper issue that requires professional diagnosis.
Preventive Measures
To prevent the Potterton E28 error and other boiler error codes from recurring, regular maintenance is essential:
Annual Servicing: Schedule an annual service with a Gas Safe registered engineer to check the flue gas thermistor, wiring, and PCB. Regular servicing helps identify potential issues before they become significant problems.
Monitor System Pressure: Regularly check the primary system water pressure and ensure it remains within the recommended range (typically 1 to 1.5 bar). Low pressure can lead to a range of issues, including safety errors and system shutdowns.
Inspect the Condensate Pipe: Ensure that the boiler condensate pipe is clear and free from blockages. A frozen condensate pipe can cause significant operational problems, particularly in colder weather.
Regular Sensor Checks: Periodically inspect all sensors, including the central heating thermistor sensor and the DHW NTC sensor, to ensure they are functioning correctly.
When to Call a Professional
If the Potterton E28 error code persists despite your troubleshooting efforts, it’s time to call a Gas Safe registered engineer. Complex issues such as deep-seated wiring faults, PCB problems, or persistent gas supply issues require professional expertise to resolve safely.
Conclusion
The Potterton E28 error code indicates a fault with the flue gas thermistor, a critical component that ensures your boiler operates safely and efficiently. By understanding the causes of this error and knowing how to troubleshoot it, you can address the issue promptly and maintain the reliability of your heating system.
For more information on common boiler errors and solutions, or to book a service with a qualified engineer, visit our boiler repair page.
Frequently Asked Questions
What does the Potterton E28 error code mean?
The E28 error code indicates a fault with the flue gas thermistor, which monitors the temperature of the flue gases in your boiler. This error often leads to the boiler shutting down to prevent overheating.
How can I fix the E28 error code on my Potterton boiler?
Start by checking the flue gas thermistor for damage, ensuring all wiring is secure, and the PCB is functioning correctly. If the issue persists, contact a Gas Safe registered engineer for further assistance.
Can I prevent the E28 error code from occurring?
Regular maintenance, including annual servicing by a qualified technician and routine checks of system pressure and sensors, can help prevent issues with the flue gas thermistor and other components.
Is the E28 error code common in Potterton boilers?
While not the most common error, the E28 code can occur if the flue gas thermistor fails or there are issues with wiring or the PCB. Regular maintenance can help reduce the likelihood of this error.
Should I call a professional if I see the E28 error code?
Yes, if you’re unable to resolve the issue through basic troubleshooting, it’s important to call a Gas Safe registered engineer to ensure your boiler is repaired safely and correctly.
