The final job is to then do the finishing works. If you have created any chases these need to be filled.

As with all electrical work, before anything is done at all, make sure that the circuit being worked on is fully isolated in the fuse box or consumer unit. To do so, either pull out the fuse or turn off the MCB. When connecting up, its necessary to ensure the brown is connected to the permanent live terminal in the junction box and the common (C) in the switch, and the blue cable (sleeved brown as it is not being used as a neutral but as a live conductor) is connected to the SL (switched live) terminal in the junction box and L1 in the switch. As we have briefly touched on, there are 2 main methods for turning a bathroom extractor fan on and off. You can either wire it into the bathroom lights so that when they are turned on the fan comes on at the same time or you can wire it to its own switch. An extractor fan is an essential part of any bathroom as it helps to remove the excess moist and humid air produced by the shower and keep any condensation build up to a minimum.As with the steps above, either a shower isolator switch is used that is normally installed outside the bathroom above the door or it’s possible to use a 3-pole pull cord switch that is usually installed in zone 3 inside the bathroom.

When it comes to electrical work in the bathroom, as this is regareded as a “special location” by the regulations, any electrical work can and should only be carried out by a Part P registered electrician so that it is ensured the circuit is installed correctly and to regulations standard, can be fully tested once complete and finally a minor works certificate can then be issued to sign everything off.

In terms of zones and where a switch can be fitted, this is generally best done in an area of zone 3, but you have to ensure that the correct rating of switch is also used, but your electrician will know for sure what to use. Tools and Products Needed to Wire a Timed Extractor Fan Firstly the cable is capped over using a PVC capping or piece of trunking. This then protects the cable in the wall. Extractor Fans with an integral timer or timed switch need a 3-core and earth supply to allow the unit to run on after a light is switched off. There are other ways to achieve this where the junction box connections are housed within the 3-pole isolation switch, but that is more complicated to explain and increases the chances of something going wrong.

Firstly the supply from the 3-pole isolator switch should be connected in to the junction box using a suitable 1mm or 1.5mm twin and earth cable to the L, N and E terminals.For both different types of units they can also be tuned on and off through normally 2 different means; they are either wired into the light, so that when it’s turned on the extractor comes on also or they have their own dedicated switch, normally as an isolator outside the bathroom above the door or inside as a pull cord switch. In this guide we take a look at how a timed fan unit or extractor fan with a built in timer is wired up, read on to find out exactly how. Safety Regulations for Electricity It must also be possible to isolate the fan by means of a pull cord switch inside the bathroom, or a fan isolation (3-pole) switch outside of the bathroom. Strip both ends of the cable to suitable lengths (manufacturer should state this in their instructions, if not see our stripping cable project here) and connect the switch end cable to the correct terminals. If however an axial fan (one through the wall) is being installed this will need to go on an outside external wall.