Bathroom Extractor Fan

[derekreid123]

I have recently acquired a new bathroom extractor fan which has a humidistat and a run on timer built in which my old one didnt.

The fan is wired through a fan isolator located just outside the bathroom adjacent the lightswitch. I have installed the new fan but doesnt seem to be working correctly, when I switch on the lightswitch the fan comes on and switching off the lightswitch the fan just goes off, so obviously the run on timer is not wired correctly.

The existing wiring from the isolator is red/yellow/blue cables, which I took to be red-live, yellow-switch live, blue-neutral. I have wired these per the instructions but the timer still does not operate.

Does anyone know why the run on timer would not be operating, could it be to do with the wiring at the isolator?

Any help would be most appreciated.

 

[Taylortwocities]

If the old fan did not have a timer, how do you know it was wired up so that you could put one in later?
You would need to get a mains tester and see if your assumption re wiring colours is correct. I do not mean a neon screwdriver. you need to determine which is really neutral and you'll need a proper tester or multimeter to do that.
If it is wired correctly, make sure the timer adjustment isnt set to minimum (they usually are, for test purposes), Wind it up a minute or two and try again.
If not have a look at the humidistat adjustment.

Do all the messing around with the isolator OFF then turn it on to test!!