Towel rail wiring

simondlh · Jan 18, 2015

Hi guys

I need some help please! I'm replacing a standard on/off switch (left pic) with a digital timer (right pic) for my towel rail. Can anyone tell me which wires from the on/off switch go into the digital timer? (L1 and N1 had two wires in them whereas L2 and N2 only had one).

Also there's nowhere for the earth wire on the digital timer, is this an issue?

[ElectriciansForums.net] Towel rail wiring

Marvo · Jan 18, 2015

Are you adding the digital timer or are you removing the switch entirely? There may be a legal requirement for the switch to remain and the timer to be added alongside it because the timer provides no means of isolation ie it can't be used to disconnect the supply.

Please ensure the circuit is properly isolated before doing any work and if you don't have test equipment to prove it's dead then rather use the main isolator on the CU to switch off the supply to the entire premises.

It's going to get tricky because it sounds like you need to get 4 wires into the N terminal and it will probably require a separate Wago connection to achieve this safely. The earths are not connected to the timer itself but must be sleeved if necessary and connected together in the back-box using a Wago or similar. The square inside a square symbol on the timer shows it's designed not to require an earth but obviously the towel rail itself does need an earth.

Given that the towel rail is probably in a high risk location such as a bathroom which means there's a higher than normal risk of fatality if there's a shock, also it's not a straight forward wire-for-wire replacement job so I'm going to strongly suggest you get an electrician to install the timer and do tests on the final circuit to ensure it's safe. If you can give a location then one of the experienced members on the forum may offer to help you for a fair and reasonable price.