Flush fit bathroom fan

The bathroom fan is "Vortice" brand flush fit in to the ceiling and I beleive it is a centrifugal type. Everything is accessed from below and the cut out in the plasterboard is around 8.5" x 8.5" square. Once the face is off I have access to the motor, control electronics and input side of the fan.

Sadly the bearings seem to be pretty much siezed as you can just about turn the blades with your fingers but it takes more force than the motor can supply so a replacement is in order

My google skills seem to have been quite poor on this occasion and I can't find a similar looking replacement. Can anyone give me some links to an extractor that will mount in the same way and preferably with minimal celing mods.

What size is the duct pipe?

The duct pipe will be 4" (100mm). PLEASE tell the model number of the old fan.

You could ask Vortice to advise the one they recommend. Maybe there's one that fits right in to the existing enclosure!
http://www.vortice.ltd.uk/contact-us.html
Or you may be able to buy a replacement fan. there are Vortice spares outlets.
http://spares2go.co.uk/browse-VORTICE-spares-m259.htm for example

Thanks chaps, after a bit of messing about I managed to find a rather well hidden rating plate with the model number on it... Its a "Vortice Ariett I T".

Replacements seem to be around 85 quid, as recommended I'll shoot them a mail and see if there are some spares available.

AYe, Fastlec have them for about £85

http://www.fastlec.co.uk/vortice-ariett-i-t-centrifugal-fan-100mm

Vortice came back to me and offered a replacement motor direct from them for around 40 quid. Hopefully an easy fix )