Keston Combi Boiler E03 error code

Hi Guys,

My five years-old Keston Combi boiler is showing an E03 error code since last night. I have restarted the boiler in order to fix the problem but no progress. Moreover, I am unable to get a gas supply from a Keston combi boiler’s burner as well. Please share your worthy suggestions.

Thanks in advance


Hi Rick,

According to the Keston Combi boiler’s user, guide an E03 error code means “faulty gas valve”. This valve controls the gas flow, which is being required by the burner & pilot light. At times, the valve becomes faulty & as a result, it does not work properly. Some other reasons behind the faulty gas valve are as follows:

  1. Defective unit
  2. Faulty connections
  3. Faulty printed circuit board
  4. Stuck valve

It is recommended to call a boiler engineer for adjusting or either replacing the faulty gas valve.