How to Fix Baxi E20 Fault?

Baxi boilers are well known for their reliability and efficiency, making them a popular choice for homeowners, landlords, and heating professionals alike. However, like any advanced heating system, they have fault codes designed to signal when something goes wrong. One such code is the E20 error, which can cause concern if you're left without heating or hot water.

The E20 fault typically indicates an issue with the primary temperature sensor, also known as the NTC thermistor. While this issue may seem daunting, it's often straightforward to diagnose and repair with professional assistance.

This blog will break down everything you need to know about the Baxi E20 fault, covering its causes, solutions, and why professional help is usually the best approach.

What Does the Baxi E20 Fault Mean?
[PROBLEM WITH A HEATING FLOW SENSOR]

The E20 error code on a Baxi boiler signifies a problem with the primary temperature sensor.

This sensor monitors the heat exchanger's temperature, helping regulate your boiler's operation. When the sensor fails or detects incorrect temperature readings, the boiler goes into lockout mode as a safety precaution to prevent further damage.

Key points to note about the E20 fault code:

• Safety First: The lockout function ensures the boiler does not operate in unsafe conditions.
• Heating and Hot Water Impact: An active E20 fault results in the boiler ceasing to provide heating and hot water services.
• Potential Causes: Common causes include a faulty thermistor, loose wiring, or damaged components.

Understanding this fault and addressing it quickly saves you from further inconvenience and costly boiler repairs.

Common Causes of the Baxi E20 Fault

Several issues can trigger the E20 code on your Baxi boiler.

Below are the most frequent culprits:

If this sensor malfunctions, it can feed incorrect data to the boiler's control system, triggering the E20 fault.

Damaged or loose connections between the thermistor and the boiler's control board can disrupt the communication of temperature readings, leading to the error code.

Although rare, the boiler's printed circuit board (PCB), which interprets the thermistor's readings, can malfunction and fail to accurately process data from the sensor.

Environmental factors such as power surges or water ingress can also result in faults with the boiler's temperature sensors or its wiring.

Diagnosing the E20 Fault

Proper diagnosis is crucial to addressing the root cause of an E20 fault. Here's how professionals typically identify the issue:

Step 1. Inspect the NTC Thermistor
Technicians will start by testing the thermistor with a multimeter to check its resistance. This reading is compared against the manufacturer's specifications for the sensor.

Step 2. Check Wiring Connections

The heating engineer checks for loose or damaged wires connected to the sensor and repairs or replaces them if necessary.

Step 3. Examine the Control Board
If the thermistor and wiring appear to be in working order, the engineer will assess the printed circuit board for malfunctions.

It's important to note that diagnosing and repairing boilers requires specific tools and expertise.

If needed, check out our blog on ‘How to Find a Reliable Engineer.’

How to Solve the Baxi E20 Fault?

While some minor boiler issues can be resolved with a simple system reset, addressing an E20 fault often requires more in-depth intervention.

Below are the steps that a professional heating engineer may take:

1. Replace the NTC Thermistor
If the thermistor is determined to be the issue, it will be replaced. This process involves removing the old component and installing a new one designed to match the boiler's specifications.

2. Repair Wiring Connections
Any loose or damaged wiring between the thermistor and boiler will need to be securely reconnected or replaced to restore proper functionality.

3. Test and Reset the Boiler
Once the faulty part is replaced, the boiler is tested for consistent performance, and the fault code is cleared via a system reset. This means that the issue is fully resolved.

Always consult a gas heating engineer.

Preventing the E20 Baxi Fault

Regular boiler maintenance is key to reducing the likelihood of encountering an E20 error. Here's how you can keep your Baxi boiler running smoothly:

Annual Servicing
Book an annual boiler service with a certified heating engineer to ensure your boiler and its components are in top condition.

Monitor Water Pressure
Check your boiler's pressure gauge regularly and ensure it remains between 1 and 1.5 bar. Excessively high or low pressure can strain the system.

Bleed Radiators Occasionally
Air trapped in radiators can disrupt water circulation, impacting the boiler's performance.

Address Issues Promptly
If you notice any unusual noises or behaviours from your boiler, have it checked promptly to prevent smaller issues from escalating into major faults.

Protect Your Boiler
Installing a magnetic filter and using quality inhibitor chemicals can help minimise debris build-up in your heating system, reducing the risk of faults.

Why Choose Professional Help?

The E20 fault can disrupt your daily routine, but it's a fixable problem when addressed by a qualified heating professional. Serviceteam's expert engineers are trained to diagnose and repair Baxi faults efficiently and offer transparent pricing. With continuous 5-star customer reviews and emergency call-out options, your boiler is in safe hands with us.

Benefits of Working with Serviceteam:

• Fully certified Gas Safe engineers.
• Transparent, upfront pricing with no hidden fees.
• Quick response times, including emergency appointments.
• High-quality replacement parts for lasting solutions.

Check out our blog site and find, E125, E119 fault and many more.

Need Help? Call Us Today!

Don't wait for a simple issue to spiral into a bigger problem. Our team is ready to get your heating system back to full functionality with a same-day solution.

Book your service today and experience the Serviceteam promise of professionalism and peace of mind.

Visit our error codes blog section to learn more about error codes.

Frequently Asked Questions (FAQs)

To reset your Baxi boiler, turn the selector switch to "R" (Reset), hold for 5 seconds, and then release. The error code will clear, showing the current temperature.

To resolve a Baxi E131 flue overheat lockout, turn the temperature control knob fully anticlockwise and hold it until the red lockout light goes off, then set it back to your desired temperature.

Find the reset button, hold it for 10 seconds, wait 2–3 minutes, then turn on heating or hot water. Your boiler should restart.

Your Baxi boiler overheats due to the E110 fault code. Common causes include a faulty thermostat, blocked heat exchanger, pump failure, low water pressure, or sensor issues.