Baxi 800 Fault Code Guide: How to Troubleshoot and Fix Common Issues
The Baxi 800 fault code system is designed to help you quickly identify problems with your boiler. Whether you’re dealing with low water pressure, ignition failure, or an overheating warning, knowing how to interpret and fix these error codes can save you time, stress, and potentially expensive repair bills.
In this guide, we’ll walk you through the most common Baxi 800 fault codes, their causes, and step-by-step troubleshooting tips to get your boiler working again.
Table of contents
Common Baxi 800 Fault Codes and What They Mean
E118 – Low Water Pressure
Cause: The boiler’s water pressure has dropped below the recommended level.
Fix: Check the pressure gauge it should read between 1.0 and 1.5 bar. If it’s low, use the filling loop to top up the pressure.
E133 – Ignition Fault
Cause: The boiler can’t ignite due to a lack of gas supply or ignition issues.
Fix: Ensure the gas valve is open and that your gas supply is working. If the problem persists, you may need a Gas Safe engineer.
E110, E125, E131 – Overheating Faults
Cause: Air trapped in the system or poor water circulation can cause the boiler to overheat.
Fix: Bleed your radiators to release trapped air and improve circulation.
Red Flashes – Fan Fault
Cause: The boiler’s fan or its connection may be faulty.
Fix: Check for obstructions or wiring issues. This may require professional help.
Red Flashes – Ignition Fault
Cause: Similar to E133, this often means the ignition system is malfunctioning.
Fix: Check the gas supply and ignition components.
Step-by-Step Troubleshooting for a Baxi 800 Fault Code
Time needed: 3 minutes
Fixing the 800 fault on a Baxi boiler involves the following steps:
- Reset the Boiler
Find the reset button on your Baxi 800 and press it for a few seconds. Some models may require holding it longer.
- Check the Water Pressure
If you see an E118 Baxi 800 fault code, top up the pressure using the filling loop until it’s within the recommended range.
- Check for Blockages
Inspect the condensate pipe (usually a white plastic pipe) for blockages or freezing especially during cold weather.
- Power Cycle the Boiler
Turn off the boiler’s power supply at the spur or fuse box, wait a short while, and turn it back on.
- Consult the Manual
Your Baxi 800’s user manual contains detailed instructions for specific fault code solutions.
- Service Mode (Advanced)
For experienced users or engineers, putting the boiler into service mode can display more detailed diagnostic information.
Conclusion
Understanding and addressing a Baxi 800 fault code doesn’t have to be overwhelming. By following simple checks such as resetting the boiler, topping up the water pressure, or clearing blockages you can often get your system running again without professional help. However, for complex issues or if you’re unsure, it’s always safest to call a qualified heating engineer. With regular servicing and prompt attention to error codes, your Baxi 800 will continue to provide reliable heating and hot water for years to come.
Frequently Asked Questions
A red light flashing below number 30 on a Baxi 105e/he/ = Ignition fault or no gas. A red light flashing below number 60 on a Baxi 105e/he = Pump failure or air in the system. Check your boiler pressure gauge, if it’s below 0.5 bar then select the low-pressure option.
The latest ranges of Baxi boilers have got a digital pressure gauge on the front. If your boiler is showing the error code A. 02.06 or H. 02.07, it is indicating that the pressure is too low for the boiler to work and needs topping up
Generally, you push the reset button and hold it down for 10 seconds. Do this only once. Wait for 2-3 minutes, as the boiler may be starting up. If the reset has been successful, then the flame will ignite in the boiler.
