BS7671:2008 said:
411.3.1.1 Protective earthing
Exposed-conductive-parts shall be connected to a protective conductor under the specific conditions for each type
of system earthing as specified in Regulations 411.4 to 411.6.
Simultaneously accessible exposed-conductive-parts shall be connected to the same earthing system individually, in
groups or collectively.
Conductors for protective earthing shall comply with Chapter 54.
A circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a
lampholder having no exposed-conductive-parts and suspended from such a point.
OK not latests, but it does not actually say if fixed or not, clearly it is flex from the "lampholder having no exposed-conductive-parts and suspended from such a point." so fact that the small amount of flex from ceiling rose to lamp holder needs a special mention to say it does not need an earth, then it seems everything else needs the earth. Yes it seems daft that a class II extractor fan still needs and earth taking to it, and common sense says take it to the FCU only and twin flex to fan, however it seems being pedantic that would not comply.
And as to fixed or the consumers installation as it is called
The Electricity Safety said:
“consumer’s installation” means the electric lines situated upon the consumer’s side of the supply terminals together with any equipment permanently connected or intended to be permanently connected thereto on that side;
since the boiler is intended to be permanently connected, even if plugged in, it comes under an EICR and all items need an earth cable available and clearly the inspector needs to remove the terminal covers for inspection.
It was pre the landlords requirements for an EICR considered that
Yes but are rf receivers run off a bit of flex from the boiler classed as fixed wiring ?
yes it is.
It seems where there are multi multi-core cables between devices your not forced to use the green/yellow core in every cable as earth, you can over sleeve, even if it is poor workmanship, still allowed, however with for example a tank thermostat the single green/yellow core has to be earth even when the thermostat is class II, and over sleeving the green/yellow would result in a code C2 at least with an EICR.
The problem is it has been like that for a long time, but until the landlord EICR electricians left the central heating to the plumbers to inspect and test, we considered it as "in-service electrical equipment" not the installation, so errors made by plumbers and heating and ventilation engineers are now coming to light. Even big stickers saying installed by Joe Blogs 2004 phone xxxx xxxxx for service, so it is very clear who made the error.