RCD question

Your first obstacle is likely to be that the switch will only have live, and and switched live wires, and no neutral. You would need to take the feed from the light fitting itself.

Ideally you would need a SELV heating pad that runs from a low voltage supply. This can be derived from a transformer placed outside of the zones.

Mains appliances in bathrooms really should have RCD protection. Using a SELV appliance is a way round this.

If your lighting circuit lacks an earth, then it sounds as if RCD protection for that circuit would be very strongly advised anyway. See:

of the vanity cabinet above the sink in the bathroom. This would get power from the light switch which is the pull cord type located on the ceiling.

vanity cabinet is 18" above the sink.

lighting circuit will be live and neutral only.

As said, RCD is definitely needed unless its a SELV heating pad run from a transformer a long way from any wetness.

NT

In message , snipped-for-privacy@gmail.com writes

Bathroom are divided into zones and the appliance should have information on it showing in which zones it can be used.