f5&f22

Hi All, I have a Flexicom 24hx Boiler about 6 years old, Been fine till about 2 months ago, then one morning it didn't come on, F22 Code. I re-set it and all was fine. Then 2 days later the same, and then F5 then off again, this went on for about four or 5 days. I called a Boiler company and...