noisy shower?

My Triton Opal had started to make a "buzzing" noise finally this morning it literally blew up - sick of this as my last Triton did the same - why do these showers only seem to last through the guarantee period - this one was actually 4 years old but still not like my original which was still going after 15 years!!!! (Not a Triton, I might add). Help before I go off Triton for good
Thanks
Polly

Polly
February 2011