I'm with Greg on this one.
What I would do, is get some test gear out and start making some tests around this installation.
To blindly go installing "whole house" surge diverters where they may not be required, would be an horrific waste of time and money, especially if it does not solve the problem.
We had over here a run of washing machine control boards, that blew for no apparent reason, this was put down to a voltage spike/disturbance.
It turned out that there was in fact an MOV on the board that after being replaced, bought the board (and the machine) back to life.
