In article ,
Set Square wrote:
This device - and its horrible little microswitches - plays a key role
in the control logic for a Y-plan system - and your symptoms are typical
of what happens when all is not well in that department.

On the ones I've seen, the micro switches are of a generic size used on
many other applications. However, as with much else, they vary
considerably in quality (and also price) between makers. A quality make
will give in its spec the expected life in number of operations - which is
vastly in excess of the likely use in this context. Assuming, of course,
they are kept within their rating.

--
*If at first you don't succeed, try management *

Dave Plowman London SW 12
RIP Acorn