Netgear Readynas Pro RMA problems

Hi Everyone,
I have already had two RMA replacements units for my 3 year old Readynas Pro Business Edition.

The first one has really loud fans and was full of dust.
The second one is a little better but the CPU fan is really loud.
Here's the health status of unit 2:
Fan SYS 932 RPM
Fan CPU 2083 RPM
Temp SYS 58C
Temp CPU 31.5C

Should the CPU fan be spinning at the high RPM, my old unit was normally at 1400 RPMs?

I think it will take sometime before they will replace this unit.

So I was wondering if anyone had a good recommendation for a CPU fan replacement?

Thanks,