A Baxi fault code tells you why the boiler has stopped or locked out. Some, such as low pressure or a frozen condensate pipe, you can safely check yourself; most others need a Gas Safe registered engineer. Find your code below. Baxi, Potterton and Main boilers show an E code, for example E133. Baxi publishes its full code list for installers only, so meanings below are those Baxi states publicly or that two Gas Safe engineer-written guides agree on. Codes can differ between models, so check your manual.
Smell gas, or a carbon monoxide alarm is sounding? Do not reset the boiler. Open windows, turn off the gas at the meter if it is safe to do so, leave the building and call the free gas emergency line on 0800 111 999. What to do →
Baxi fault codes and what to do
E133You may be able to fix this
What it means: Gas supply interrupted or the flame failed to ignite. Baxi also lists it among the codes shown when the condensate pipe is frozen.
What to do: Check other gas appliances and prepayment credit. In freezing weather, thaw the condensate pipe with warm (not boiling) water, then restart.
E119You may be able to fix this
What it means: Low water pressure. Baxi also lists it among codes that can appear with a frozen condensate pipe.
What to do: Check the gauge and repressurise to the level in your manual. In a cold snap, check the condensate pipe too.
E118You may be able to fix this
What it means: Water pressure too low.
What to do: Repressurise using the filling loop as shown in your manual. If it keeps dropping, there may be a leak.
E28You may be able to fix this
What it means: Flue or sensor fault, most often caused by a frozen or blocked condensate pipe.
What to do: Baxi's advice: switch off, warm the exposed condensate pipe along its length, then restart. Repeat if needed.
E125You may be able to fix this
What it means: Circulation fault in the primary (heating) circuit, often linked to low pressure.
What to do: Check the pressure and bleed radiators if they are cold at the top. If it returns, call an engineer.
E117Engineer needed
What it means: Water pressure too high.
What to do: Do not keep resetting. A Gas Safe engineer should check the filling loop, expansion vessel and pressure relief valve.
E110Engineer needed
What it means: Safety thermostat operated: the boiler has overheated.
What to do: Check the pressure and that radiator valves are open. If it returns, call an engineer.
E130Engineer needed
What it means: Flue sensor operated (flue overheat).
What to do: Switch off and call a Gas Safe engineer.
E160Engineer needed
What it means: Fan fault.
What to do: Needs a Gas Safe engineer.
E20Engineer needed
What it means: Central heating temperature sensor (NTC) fault.
What to do: Needs an engineer.