Of course safety, the protection of life and property is important, but as you say the line has to be drawn somewhere, who should we trust to draw that line, IMO it should be an independent arbiter, does one exist already?I get what you're saying Mike. The line has to be drawn somewhere though, between unskilled operatives carrying out routine replacements, and relying solely on a maintenance contractor that specialises in the particular system in question.
I for one would err on the side of protection of life and property.