The question of legality in carrying out work on your own installation has
been covered before in this NG. The consensus has been that you do not have
to employ a CORGI fitter if the work that you carry out is done competently.
I guess that in the ultimate circumstances a court would decide if you had
been competent.

However does anyone know if the above is also true for the following
specific circumstance:

I returned from holiday to find that my gas had been turned off by Transco
after my neighbours had reported what they thought was a smell of gas
(incorrectly I believe). The Transco people couldn't detect any gas leak but
took the easy/safe/cover your orse option of switching off the supply and
putting a notice through my door with the lowest of the three categories
Concern for Safety ticked. The notice says: The gas equipment must not be
used. It is an offence to continue to use an unsafe appliance or
installation until tested by a CORGI registered installer.

So is it an offence or does the competency thing apply?

I hope that those of you who don't like your neighbours would not dream of
using the above to land them with a CORGI McWhopper invoice :-)