Bathroom extractor - advice needed please

[Onlyforaday]

Hello, we had a bathroom fan installed a year or so ago which was meant to be very efficient but it's total rubbish! We still have mould to be dealt with every few weeks. It opens up like some sort of space craft (looks like petals opening out very slowly) but there's hardly any suction when we hold a piece of paper up to it to check.
The electrician we used is not replying to us but we desperately need another installing.
Can anyone please recommend a powerful unit to me? Our bathroom is 8' x 8'

Thank you.

Does it vent outside or to the loft space?
Asking at a builders merchant or electrical supplies shop would be your best bet. Explain the problem and they should be able to supply something. It is likely to be ugly and noisy

Thank you. Yes I will pop in to one of the plumbing centres next week with measurements. It vents through the loft via a hose and then out under the eaves. I was hoping for something quiet but would sacrifice that for efficiency any day.

If the fan unit is placed further down the pipe thing away from the ceiling it will be quieter. I think that’s a slightly tricker install

Ah thanks for that. The unit we have is fixed on to the ceiling but that's something to think about with the new one.