What is the purpose of the isolation switch and is it necessary? Also why does it need to be within 1 metre of the rails? Can the transformer be installed sub floor (where I have easy access if necessary)
The isolation transformer can be installed subfloor, provided that
insulation is removed to a 300mm radius and also assuming that the
transformer will be accessible for replacement in the future.
DCS recommend that the isolation switch be within 1 metre of the towel
rail so that the switch is easily identified with the appliance. There
must be a switch for the towel rail somewhere to switch it off in the
event of a fault.
Every towel rail is supplied with a timer that is also controlled by the switch.
The switch for low voltage towel rails, such as the Vega, is typically
a separate switch mechanism on the light switch plate for the whole
bathroom (clearly marked). For example you may have lights, extractor,
towel rail and heating on the same switch plate.
Although this is common practice, and safe, we still recommend that
the switch for the towel rail be a separate switch plate located close
to the rail itself. The installation instructions mention both