Potterton / Baxi E133 Fault Code May 14, 2021 Potterton / Baxi E133 Error Code Repair In Birmingham.Sometimes your boiler may show an error code. These help to determine if there is a problem with the boiler, gas supply or heating system and how to resolve it. Some problems are easy to fix and you can carry out a few simple steps to do it yourself, while others need to be sorted out by a Gas Safe registered engineer.The error code will appear on the facia display as either two or three numbers, preceded by the letter ‘E’. For example, code E133 will be displayed by 'E1' alternating with '33'. E50 is shown as 'E' then '50'.Error code E133 usually indicates that gas supply has been interrupted, ignition has failed, or the burner flame has not been detected. In this case, the burner flame was not being detected due to a faulty flame sensing electrode. The part was replaced and the boiler was put back into full, safe working order.