Baxi boilers are known for their reliability, but like all boilers, they can occasionally develop faults. When this happens, the boiler will display an error code to help identify the problem. Some of these faults can be fixed easily, while others will require a professional repair.
If your boiler isn’t displaying a fault code but isn’t working, check the following:
Gas supply: Ensure your gas supply is on by checking other gas appliances like your hob.
Electricity supply: See if your boiler’s display is on and check your fuse box.
Water supply: Make sure your taps are running with normal pressure.
Prepay meter: If you have a prepay gas or electricity meter, ensure you have enough credit.
If everything appears to be in order but your boiler still isn’t working, it may be time to call a Gas Safe engineer.
Fan error – fan not running correctly or wiring issue
E50
Hot water outlet thermistor fault
H.01 – .00
Temporary loss of communication between gas valve and boiler board
H.01 – .05
Maximum difference between flow and return temperature exceeded
H.01 – .08
Flow temperature increasing too fast in heating mode
H.01 – .14
Maximum flow temperature value exceeded
H.01 – .18
No circulation of water
H.01 – .21
Flow temperature increasing too fast in DHW mode
E118
Low water pressure (< 0.5 bar)
E128
Loss of flame during operation
Baxi System Boiler Fault Codes
Applies to:
Baxi 600 System (15kW – 24kW)
Baxi 800 System (18kW – 24kW)
Baxi Platinum+ System (32kW)
Baxi Megaflo System (15kW – 32kW)
Error Code
Issue
E20
Central heating thermistor sensor error
E40
Central heating return thermistor fault
E78
Water pressure sensor fault
E125
Primary water circulation fault
E119
Low water pressure – add water to the system via the filling loop
E133
Ignition failure or gas supply issue
E160
Fan or fan wiring fault
Baxi Regular (Heat Only) Boiler Fault Codes
Applies to:
Baxi Solo HE A (12kW – 30kW)
Baxi 200 Heat (12kW – 30kW)
Baxi 400 Heat (12kW – 30kW)
Baxi EcoBlue Heat (12kW – 24kW)
Baxi 630 Heat (30kW)
Error Code
Issue
E28
Flue thermistor error
E53
Flue obstruction
E55
Calibration required
E110
Boiler overheat or safety thermostat tripped
E125
Primary water circulation fault
E133
Ignition fault – Check gas is turned on
Most Common Fault Codes (Applicable to All Models)
Error Code
Issue
E110
Boiler overheat or safety thermostat tripped
E118
Low water pressure (< 0.5 bar)
E125
Primary water circulation fault
E128
Loss of flame during operation
E119
Low water pressure – add water to the system via the filling loop
If you encounter one of these common faults, check your boiler’s pressure gauge and try resetting your system. If the issue persists, contact a professional.
How to Reset a Baxi Boiler
If your Baxi boiler has locked out due to a fault, try resetting it:
Find the reset button – It’s usually on the front panel.
Press and hold the button – Hold it for 3-5 seconds until the boiler restarts.
Wait for the boiler to reboot – If the fault persists, check the error code and refer to this guide.
If the boiler continues to lock out, contact a Gas Safe engineer.
When to Call a Gas Safe Engineer
While some faults can be resolved by checking the pressure or resetting the boiler, others require professional help. If you experience:
Recurring error codes
No heating or hot water despite normal pressure
Gas supply issues
Strange noises or leaks
It’s best to call a Gas Safe registered engineer for a full inspection and repair.
Book a Boiler Repair with WarmZilla
If your Baxi boiler needs repairs, WarmZilla can help. Our Gas Safe engineers are available across the UK for fast and reliable service.
Andrew is a Gas Safe Engineer who also writes about the boiler and home service industry. With years of hands-on experience under his belt, he now focuses on sharing his knowledge—and making his own tea.
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