sanivite 3 leaking?

hi all,i have a sanivite 3 that when i turn it on it makes a rather loud whering noise every 5 seconds & water spits out of the exit pipe.
i'm a photocopier service engineer so no the basic electrical stuff & motors can i remove the box & take a look inside & what should be obvious.
if i have to bye a new one do you just plonk it inplace of the old one ?

colin white
January 2009