Humidistat Extractor Fan

[MartK]

Hello. The builder just finished our bathroom renovation and has done a great job. However, he forgot to install the extractor fan we asked for - it was meant to be connected to the light switch but there is now no way to fit it without wrecking the finish. So I asked him to install a humidistat fan and opted for the Xpelair C4HTS which has gone into the ceiling. It was supposed to be wired to the mains and come on based on humidity levels in the bathroom with no need for a switch/pull cord to operate it. Its been wired to an isolation switch in the loft space above (easy to access through the dormer above). The cable is 3 core plus earth. The grey wire is cut off and not connected to the fan as is earth. L and N go to corresponding terminals in the fan and there was a short wire connecting L to what I believe is Switched L in the fan.

Now as soon as the isolation switch in the loft is turned on the fan spins and won't stop. Tried tinkering with humidity and timer settings to no avail. The only way to stop it is through the loft isolation switch which obviously cuts power to the fan.

I removed the L to SL wire yesterday and thought I had solved it. The fan didn't spin when the isolation switch was turned on and did come on when I created some steam but turning on the shower. HOWEVER, it wouldn't stop spinning even after all the steam had cleared and I waited for some considerable time to be sure. Had to flip the isolation switch to stop the fan.

I am assuming the fan is either faulty or there is a wiring issue and could do with some advice. I have asked to return the fan and ordered a Ventaxia VASF100HT instead but thought I would seek some advice before changing them over.

Any help greatly appreciated. Hopefully the above is clear but let me know if not.

Thanks a lot

 

[CBW]

It does sound like your diagnosis, faulty fan or faulty wiring, to check the latter would need a 2 pole voltage indicator or multimeter. Just out of interest, if the fan is in the ceiling, presumably the lights are too, why couldn’t you have the fan you originally wanted?

 

[MartK]

Hello CBW,
The fan has gone in the corner of the ceiling. Above that on the floor above is a void between the dormer and the outer wall. Above most of the bathroom ceiling, including where the lights are is another bathroom - just tiled and finished too. I dont think there is a way to get a wire from the lightvswitch to the fan. That said I didnt spend much time thinking about it as I assumed the seperately wired hunidistat fan presented an wasier solution. Just need to figure out how its supposed to be wired or if the fan I have is faulty. Do you know how it should be wired up based on my description above? Thanks

 

[MartK]

Looks like I've resolved this. I have left the short wire connecting L to SL off and altered the hunidity setting again. It now seems to be working ok. Comes on during a shower and turns itself off after a period of time.