Extractor fan wiring, replacements timed and switched

Extractor fans tend to get a lot of use, as for the most part extractor fan wiring requires the use of the lighting circuit in your bathroom to provide the electricity, so everytime the light pull switch is turned on the fan activates. There are two different fans on the market, timed and switched, with two different functions, one operates in conjunction with the switch; light on, fan on, light off, fan off. The other functionality is where the fan works for a timed period after the switch is pulled to turn the light off. From a wiring point of view the difference between the two types of fan is that the timed fan has a ‘permanent live’ phase for the timer which will keep the fan running after the light switch has been pulled off. The ‘switched’ live keeps the fan running when the light is switched on. 

Time guide