BAXI boilers have been a household name for years, known for their reliability. However, even the most dependable systems can experience issues over time. This guide covers troubleshooting steps, error codes, and practical solutions for BAXI combi boilers, including the 100, 200, 300, 400, and 600 series, as well as the Duo-tec and EcoBlue models.
1. First Step: Check Your Warranty
Before diving into diagnostics, confirm if your boiler is still under warranty. BAXI offers warranties ranging from 2 to 10 years when installed by certified engineers. However, keeping up with annual maintenance is essential to ensure the warranty remains valid. If your system is still covered, many repairs can be performed free of charge, provided routine servicing is documented.
If your boiler is no longer under warranty or you’re uncertain, professional engineers may still provide repairs. If repair costs seem excessive, comparing quotes for a new boiler can be a cost-effective alternative.
2. Restart the Boiler to Resolve Minor Glitches
Sometimes, a fault code appears due to a minor or temporary issue that doesn’t require technical intervention. Restarting the boiler may reset the system. Here’s how:
- Locate the reset button on the front panel of the boiler.
- Press and hold the button for 1 to 3 seconds until the unit reboots.
- If the fault persists after a restart, move on to the troubleshooting section.
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3. BAXI Boiler Error Codes: A Quick Overview
Below is a breakdown of common BAXI error codes and recommended actions.
Error Code | Issue Description | Engineer Required? | Estimated Repair Cost |
---|---|---|---|
E09 | Gas valve connection issue | No | Reset recommended first |
E15 | Gas valve fault | No | Reset recommended first |
E20 | Central heating NTC sensor fault | Yes | £200–£300 |
E28 | Flue fault | Yes | £150–£300 |
E40 | Central heating return fault | Yes | £60–£100 |
E55 | Calibration required | Yes | £60–£100 |
E109 | Pre-circulation fault | Yes | £100–£200 |
E110 | Safety thermostat tripped | No | Reset recommended first |
E117 | Water pressure too high | No | Adjust gauge (£50–£100) |
E118 | Water pressure too low | No | Adjust gauge (£50–£100) |
E125 | Circulation fault (primary) | No | Reset recommended first |
E128 | Flame failure detected | No | Reset recommended first |
E130 | Flue NCS operated | Yes | £50–£100 |
E133 | Gas supply issue or ignition failure | No | Reset recommended first |
E134 | Gas valve open without gas flow | No | Reset recommended first |
E135 | Gas supply interruption | No | Reset recommended first |
E154 | Flow/return sensor temperature fault | Yes | £50–£100 |
E160 | Fan fault detected | Yes | £150–£200 |
E270 | Circulation fault (dry fire) | Yes | £100–£150 |
E321 | Hot water NTC fault | Yes | £200–£300 |
E384 | False flame detected | No | Reset recommended first |
4. When to Call a Gas Safe Engineer
Many BAXI error codes can be resolved by a simple reset. However, persistent issues—especially those related to gas valves, fans, or sensors—require professional attention. If your boiler is under warranty, contact BAXI directly. For out-of-warranty boilers, ensure you hire a Gas Safe-certified engineer to perform any repairs safely and effectively.
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5. Handling Pressure Issues
Water pressure problems are among the most common issues with BAXI boilers.
- High Pressure (E117): Use the pressure release valve to bring it down to the recommended range (1.0–1.5 bar).
- Low Pressure (E118): Top up the system using the filling loop. If pressure adjustments don’t resolve the issue, contact an engineer for further inspection.
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6. Recurring Flame Failure (E128/E133)
If the boiler is unable to ignite, it may display E128 or E133. Causes can range from a gas supply interruption to blocked burner components.
- Verify your gas supply is intact.
- Restart the boiler and monitor for recurrence.
- Persistent issues may indicate a defective gas valve or burner requiring replacement.
7. Fan-Related Errors (E160)
When the fan responsible for airflow within the boiler malfunctions, E160 will appear. Fans can deteriorate over time, leading to performance issues.
- If under warranty, contact BAXI for repair.
- For out-of-warranty boilers, expect costs between £150–£200.
8. Flue and Circulation Faults (E28, E270, E125)
The flue expels gases safely, and any obstruction can result in E28 or E130 errors. Similarly, circulation faults like E270 indicate poor water flow within the system.
- Clean the flue if accessible and safe to do so.
- Call an engineer for deeper inspections and repairs.
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9. Boiler Beyond Repair? When to Replace
If your boiler frequently malfunctions or repair costs are mounting, it might be more practical to replace the unit. Modern boilers are more efficient, reducing energy costs in the long run. Here are a few options with installation costs for consideration:
Boiler Model | Warranty | Starting Price |
---|---|---|
Viessmann Vitodens 050-W | 10 years | £1,990 |
Viessmann Vitodens 100-W | 10 years | £2,455 |
Worcester-Bosch 4000 | 10 years | £2,890 |
Worcester-Bosch 8000 | 10 years | £3,200 |

10. Maintaining Your BAXI Boiler: Prevention Tips
- Annual Servicing: Schedule regular maintenance to catch issues early.
- Monitor Pressure: Regularly check water pressure to prevent unnecessary shutdowns.
- Clean the Flue: Ensure the flue is clear to maintain proper airflow.
- Prompt Repairs: Address minor issues quickly to avoid costly repairs.
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11. Conclusion: Quick Resolutions for Common Problems
While BAXI boilers are generally reliable, every boiler may encounter occasional issues. Simple resets can solve many minor glitches, but recurring or severe problems require professional help. Knowing the meaning behind error codes allows you to act quickly, ensuring the longevity and efficiency of your heating system. If repairs are becoming frequent, consider upgrading to a more efficient boiler.
For further assistance, explore boiler quotes from trusted engineers or consult with LETsheat for reliable service and affordable payment options.
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FAQs
When should I call a professional for BAXI boiler issues?
You should call a professional if you encounter persistent error codes, unusual noises, leaks, or if you’re unable to resolve issues through basic troubleshooting. It’s crucial to ensure safety and proper function, especially with gas appliances
What should I do if my BAXI boiler is making unusual noises?
Unusual noises from a BAXI boiler, such as banging or gurgling, can indicate issues like air in the system or low water pressure. Check the pressure gauge and bleed the radiators if needed. If the noises continue, it’s best to contact a professional.
How can I reset my BAXI boiler?
To reset your BAXI boiler, locate the reset button on the control panel. Press and hold the button for a few seconds until you see the display indicate that the boiler is resetting. If the error persists, further troubleshooting may be necessary