Updated: 30th May, 2025
The complete guide to what each Baxi boiler error code means and how to fix it!
Is your Baxi boiler not working and displaying an unusual error code on its screen?
Worry not as these codes can be a great indication of what it is that is wrong with your boiler, helping either yourself or an engineer to know what needs to be done in order to fix it!
In this guide, we will be explaining what each Baxi fault code means and how to fix it.
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To begin with, it’s important for you to know how to reset your Baxi boiler model as this can often be the fix for many smaller issues.
The way in which you reset your boiler depends on what type of button or switch it has.
If your Baxi boiler has a dedicated reset button, simply press it until your boiler resets itself and the pilot light relights.
Sometimes, your boiler may lock out. This can be identified by the RED Lockout light constantly illuminating or flashing. In this case, simply hold the reset button until the red light goes away.
If your boiler has a boiler thermostat control knob, turn it fully anticlockwise and then turn it back to your desired setting.
If your boiler has an ON/OFF/SELECTOR switch, open the pull down panel and turn the selector switch to R (Reset) and hold for at least 5 seconds before releasing.
Now let’s jump into what each boiler error code means and how you can fix it.
Fault Code | Issue | How to Fix |
|---|---|---|
E20 | Central heating NTC error. | Your boiler will likely lock itself out. Call out a Gas Safe Registered Engineer to take a look. |
E28 | Error with the NTC, flue, air pressure switch or a blocked flue or condensate pipe. - Usually caused by a frozen pipe. | Turn your boiler off at the control panel and turn off the electricity at the wall. Locate the frozen pipe and warm it with either a hot water bottle or warm water poured from a watering can (NOT BOILING WATER) Turn the power back on and restart your boiler. |
E50 | Hot water NTC error. | Call out a Gas Safe Registered engineer to replace the hot water sensor and seal. |
E110 | Overheating error. | Bleed your radiators. If the issue persists, call out a Gas Safe engineer to check for blockages in the system. |
E119 | Low pressure. | Top up your boiler pressure. If the issue persists, call out a Gas Safe engineer. |
E125 | Circulation fault caused by low pressure. | Top up your boiler pressure. If the issue persists, call out a Gas Safe engineer. |
E130 | Flue operation error. | Check the outside flue terminal isn't blocked by a bird, or trees etc, and clear it if it is. If the issue persists, call out a Gas Safe engineer. |
E133 | Frozen condensate pipe. | Turn your boiler off at the control panel and turn off the electricity at the wall. Locate the frozen pipe and warm it with either a hot water bottle or warm water poured from a watering can (NOT BOILING WATER) Turn the power back on and restart your boiler. |
E160 | Fan system fault. | Call out a Gas Safe engineer to check fans. |
E193 | Pre circulation fault. | Call out a Gas Safe engineer to check the heat pump or heat exchanger for blockages. |
Fault Code | Issue | How to Fix |
|---|---|---|
110 | Overheating error. | Bleed your radiators. If the issue persists, call out a Gas Safe engineer to check for blockages in the system. |
117 | Water pressure too high. | Bleed your radiators. If the issue persists, call out a Gas Safe engineer to check for blockages in the system. |
118 | Water pressure too low. | Add water via the filling loop. If the pressure drops again, call out a Gas Safe engineer. |
125 | Circulation fault caused by low pressure. | Top up your boiler pressure. If the issue persists, call out a Gas Safe engineer. |
133 | Safety time to establish flame exceeded. | Ensure that the gas supply has not been turned off and reset your boiler. If the issue persists, call out a Gas Safe engineer. |
E10 | Outside sensor error. | Call out a Gas Safe Registered engineer to check the outside sensor. |
E20 | Central heating NTC error. | Your boiler will likely lock itself out. Call out a Gas Safe Registered Engineer to take a look. |
E28 | Error with the NTC, flue, air pressure switch or a blocked flue or condensate pipe - usually caused by a frozen pipe. | Turn your boiler off at the control panel and turn off the electricity at the wall. Locate the frozen pipe and warm it with either a hot water bottle or warm water poured from a watering can (NOT BOILING WATER) Turn the power back on and restart your boiler. |
E54 | Hot water sensor error. | Call out a Gas Safe Registered engineer to replace the hot water sensor and seal. |
E79 | Water pressure sensor and/or pump defective. | Call out a Gas Safe Registered engineer to check the water pressure sensor and/or pump. |
E100 | Internal clock time error on printed circuit board. (PCB) | Call out a Gas Safe registered engineer. |
Have you got a Viessmann, Worcester Bosch, Alpha or Ideal boiler and aren’t sure what the fault code means? Worry not! We’ve also created guides to the most common codes for all of these brands.
Check them out below:
Ideal Boiler Error Codes
For more advice and guidance when it comes to your home heating, check out our helpful blogs or get in touch with our friendly team at iHeat today!
The error lights on a Baxi boiler indicate specific faults or operational statuses. Common lights include a green light for normal operation, flashing red or orange lights for fault conditions, and specific sequences that pinpoint issues like pressure drops or ignition failures. Refer to your boiler's manual for a detailed explanation of each light pattern.
To reset a Baxi boiler error code, you can typically press the reset button on the boiler's control panel for a few seconds. If the fault persists, the error code may reappear, indicating that further troubleshooting or professional assistance is required to resolve the underlying issue.
An E1 fault code on a Baxi boiler usually indicates an issue with the boiler's thermistor or a problem with the water's temperature being too high. It suggests that the thermistor may need replacing or there's a fault in the heating system preventing proper water circulation.
If your Baxi boiler isn't firing up for central heating, it could be due to several issues, including low water pressure, a faulty thermostat, ignition problems, or a blocked condensate pipe. Checking the boiler pressure and ensuring that the thermostat is set correctly can be initial troubleshooting steps.
If your boiler is firing but the radiators remain cold, the issue could be air trapped in the system, a problem with the pump circulation, or blocked radiators. Bleeding the radiators to remove air or checking the pump for operational issues can help resolve this problem.
Fixing a boiler that won't fire up involves checking for common issues such as low pressure, a tripped fuse, or a closed gas valve. Increasing the pressure, resetting the electrical supply, or ensuring the gas supply is open can often remedy the problem. If these steps don't work, it's best to contact a professional heating engineer.
The most common boiler problem is low pressure, which can prevent the boiler from operating efficiently. Other frequent issues include frozen condensate pipes, radiator faults, and ignition problems. Regular maintenance and prompt repairs can help prevent these issues from affecting your boiler's performance.
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