...really?
You make a broad statement saying the majority of gas engineers don’t service properly... such a self righteous comment.
And you’re always banging on about how you do such a superior service, stripping boiler to nothing but a casing, probably completely disregarding the manufacturers instructions and costing the customer unnecessary elevated bills to just satisfy your need to feel all important and qualified. It’s got absolutely nothing to do with doing a good service, you treat a service as a cash cow and I can quite believe you charge £200 or more for a couple of hours of your time.
And on a final note, you can collect all the ecotec pro and plus and anything other shat that Vaillant make and stick em on a big train, back over to your motherland.