Just imagine how it would pan out if the HSE took a diyer before a judge.
HSE: this man is incompetent your honour
Judge: please list the faults in his gas hob installation
HSE: there were no fault's m'lord it was a text book installation
Judge: I'm fining the HSE 5000000 pounds for wasting courts time. Case closed
But in a situation where a DIYer has done gas work in his own home, and due to incompetence or inexperience an event occurs which the HSE get to hear about. Is he then liable?
Anyway, there seems to be consensus that doing DIY gas work in one’s own home is not in itself illegal. But in many posts on this forum gas safe guys have stated that it’s illegal for a householder to so much as remove an outer panel from a boiler if he is not gas safe registered. It appears that is not correct (though they have an obvious motive for saying it).