Bathroom extractor problem

OK so my bathroom extractor fan is not working (connected to lighting circuit).

I bought a replacement of the same make but not the exact model. The replacement I bought was a manrose with timer - but the original didn't have a timer so I just by passed the timer circuit - that shouldn't cause a problem should it?

Anyway it still didn't work so I followed the cabling to a unit in the loft space (not the 3 pole isolator switch). This was also a manrose device but it had no obvious cut out switch or fuse. There's a red led on the front which was off - should that be on permantly or only when the fan is running? If it should be on then can I assume that device is faulty (I think it's some sort of humidity/timer device although the fan in question doesn't timer overrun).

Thanks

Andy

Right - I now suspect this device is a transformer so I should be looking to get a low voltage fan as a replacement - but to determine if the fault is with the fan or the transformer, does anyone know if that LED should be all the time or just when the fan is operating?

Thanks again.

Usually, when a fan has a timer which you do not wish to use, you would connect the switched live terminal to the permanent live terminal with a small piece of live wire.
The fan you have bought as a replacement - you need to make sure it is the same type as your old one, i.e. that it is a 12V fan (assuming your other one was, and it was using the transformer you mention), etc.

Thanks pbar.

I guess I just need to determine if the fault is the transformer or the fan. Would connecting an LV type bulb to the wires at the fan do the trick?