Yes, I understand the issue with maintenance, but bear in mind that satisfying the implication of a particular regulation or manufacturer’s instruction inevitably means a connection arrangement that can introduce its own issues. One of the biggest landlords in these islands reports a high incidence of burning at the terminals of those ubiquitous 45A pullcord switches, especially on the neutral. 

Are local isolators required for mechanical maintenance in general? I can appreciate the need for an isolator for mechanical maintenance of an oven/hob, for instance, to facilitate cleaning. However, what kind of mechanical maintenance would a shower entail?

Also according to manufacturers instructions It is important to use an isolating switch for safety reasons, such as preventing accidental activation of the shower, protecting the shower from power surges, and allowing easy access for maintenance or repair ? 

AMK said:

Are local isolators required for mechanical maintenance in general?

Not according to BS7671. Local isolation is not required for any appliance.

AMK said:

Are local isolators required for mechanical maintenance in general?

Not according to BS7671. Local isolation is not required for any appliance.

So What does switching off for mechanical maintenance mean on an EICR? What part of the installation does it apply to? Are local isolators not required in a domestic property. What is the following referring to on a EICR?

Presence and condition of appropriate devices (464.1; 537.3.2) Capable of being secured in the OFF position where not under continuous supervision (464.2) Correct operation verified (643.10) Clearly identified by position and / or durable marking (537.3.2.4)