Keston 40 error E03


I have a Keston Combi 40 model, which is 6 years old and it worked really fine till now. Last week it showed error E03. I restarted and ┬áit helped… for a while. Today boiler switched itself off showing again E03 error message. What does it mean and how to fix it?



Hi Jim

Error 03 means that your gas valve is either not connected or faulty. Considering it was working for the last 5-6 years, I would say it is faulty and need to be replaced. You can replace yourself (if you have proper qualifications) or call Keston service. They will exchange it in less than an hour