Almost the victim of a 3rd pump, I followed the instructions, and it has been over three years without a hitch. The guys at MB confirmed that the pressure switch is the culprit sometimes, but overadjusting it could cause havok with the other elements. They also confided that NB wont let them open the pump or tweek it for liability issues.
If you look at it it has safeties, purges the lines of moisture, resets the elements.