Central Heating Issue

[jim8flog]

I have watched many ' how to videos' on youtube and I have a very good background in electro mechanical engineering but very often I have just gone out and bought a new one.

I must admit the how to video on testing the expansion vessel on a Vaillant boiler and another on how to fit a new one did make it look easy but one has to question at what point does working on a boiler without the correct gas certificates allow one to go.

 

[Reemul]

Thanks for all the advice, gonna call someone out tomorrow and see how much it's gonna cost