Immersion Heater
16 A radial via a 20 A double-pole switch with neon, to heat-resistant flex.
● Line● Neutral● Earth
Tap any wire, switch or device to see what it is.
Useful Information
A 3 kW element draws ~13 A. Supplied on its own radial — not from a ring.
Important to know
- Use heat-resistant (butyl / HOFR) flex from switch to element (522.2).
- Thermostat must be connected; bond metal cylinder only if required as extraneous.
- 30 mA RCD where required by 411.3.3 / 411.3.4 or special location.
BS 7671:2018+A4:2026 references
433.1522.2554.2
Study notes paraphrased — check against your copy of BS 7671.