problem thermal cyclers (techne>

[Grant McKegney]

Our lab Techne III thermal cycler now fails to maintain (and sometimes
achieve) the programmed temperatures.  No longer can we cool a sample
below 14 degrees C.  If we wish to anneal at, say 57 degrees for 30 sec,
the actual temps would be:
59 degrees (start timing+0)
56 degrees t=10
56.2 degrees t=20
56.5 degrees t=30
So temp would never actually stabilize at 57.

Question: does anyone else have/had this problem with this model?  Is it
fixable, or do we just replace it?