A sad story for all involved.

I really do think that no amount of legislation would stop things like this happening, unless you stop the general public being able to buy parts from factors or retailers and even then you would have to stop supply of second hand parts aswell.

I know I should not do any gas boiler repairs or wiring etc but I can go into most plumbing trade supplier and buy a new boiler pump, circuit board or gas valves, so who is to know what I am up to until something goes wrong?

It's a bit like - if it is illegal to carry big knives why is it legal to sell them.

Legislation would put the burden on the trade not the illegal diy mechanic so why not prevent diy repairs without burdening the trade, could this be done?

Graham