Baxi Error Codes & Diagnostics
Complete diagnostic directory for official Baxi fault codes. Verify root causes, safe troubleshooting steps, and replacement part numbers before calling a technician.
Baxi E110: the overheat lockout that is really a circulation message
Baxi uses E110 for an overheat condition, where the boiler has exceeded its permitted maximum temperature or the safety thermostat has tripped. The measurement is genuine, but heat only accumulates when something stops carrying it away, so the investigation belongs to the water side of the system more often than to the burner. Applies to: Baxi domestic gas boilers using the E-series fault codes listed in Baxi support material Baxi publishes E-series codes across several domestic ranges, and the detail behind a number can differ between them. The list on the label behind the casing flap of your own appliance governs, and a Potterton or Main boiler from the same group carries its own published list even where components are shared. Owner-safe checks: Check the system pressure gauge on the boiler and write down the reading while the system is cold. | Feel every radiator after a heating attempt and record which warm up, which stay cold, and where on the panel the cold begins. | Note any noise from the boiler and whether it coincides with firing, and stop using the heating if kettling is present. Qualified technician: Pump testing and replacement, venting a sealed primary circuit, cleaning or flushing a system, and resetting a tripped safety thermostat are Gas Safe registered tasks. | A boiler that boils audibly should not be run while waiting for an appointment, because each episode damages the heat exchanger surface further.
Baxi E119 fault code: low system pressure and how to clear it
Baxi assigns E119 to low water pressure in the heating system, below the level the boiler needs to operate. It is cleared by repressurising to between 1 and 1.5 bar with the filling device fitted to the boiler, and it points to a leak only if the pressure will not stay up afterwards. Applies to: Baxi and Potterton domestic boilers that display E119 This covers Baxi and Potterton boilers whose published fault guidance lists E119. Baxi uses E118 for a related low-pressure condition on some models, so match the exact digits, and confirm the boiler model before choosing a filling method. Owner-safe checks: With the boiler off, read the gauge and, if it is low, admit water with the boiler filling device until it reads 1 to 1.5 bar cold, then close the device fully. | Keep a short note of each repressurise, the date, and the pressure before and after, so a repeat loss can be measured. Qualified technician: A pressure that will not hold, visible damp or staining, a dripping outside overflow pipe, or any expansion vessel or internal check needs a Gas Safe registered engineer.
Baxi E133: failed ignition and the frozen-condensate clue
Baxi defines E133 as a failed ignition condition. In freezing weather, a blocked frozen condensate pipe can contribute on installations with an external condensate run, but E133 is not a frozen-pipe detector. Fuel supply, ignition, flame proof, condensate, venting, and controls remain professional diagnostic branches. Applies to: Baxi domestic boilers covered by the manufacturer E133 guidance This guidance applies only to Baxi boilers whose own user or service instructions list E133. Product generation, country, and fuel setup matter; confirm the complete model before using any reset or thawing instruction. Owner-safe checks: Confirm the full model and weather, check other gas appliances, and inspect only an easily accessible ground-level external condensate section. Qualified technician: Inaccessible or internal condensate, recurring freezing, gas supply, ignition, electrode, combustion, vent, flame-proof, and sealed-case work require Gas Safe service.
Baxi E160: fan or fan wiring, and why the boiler will not compromise
Baxi publishes E160 as a fan or fan wiring fault. Two distinct situations sit inside that phrase: a fan that is not turning at all, and a fan that is turning but whose speed the control cannot confirm. Both stop the boiler, and telling them apart from outside the casing starts with whether you can hear anything. Applies to: Baxi domestic gas boilers using the E-series fault codes listed in Baxi support material The E-series codes are published by Baxi across several domestic ranges, and the same number does not necessarily carry the same detail on every one. Read it against the list on the label behind your own casing flap, and treat lists compiled for other manufacturers as unrelated. Owner-safe checks: Stand near the boiler during one start attempt and note whether any fan sound occurs, and for how long. | Write the code down exactly, since Baxi E-series numbers are three digits and adjacent numbers mean different things. | Think back over the last few months for anyone who has worked on the appliance or the circuits feeding it, and note what they did. Qualified technician: Fan testing, wiring inspection, and fan replacement on a room-sealed gas appliance are Gas Safe registered tasks in the United Kingdom. | Leave the front of the appliance exactly as it is. That panel is part of the sealed enclosure separating combustion from room air, and it is not an inspection hatch.