Jules Richardson wrote:

Every once in a while I worry about our well pump - if some catastrophic
failure of the plumbing occurred then the pump would just run and run
until something broke. I wonder about adding a thermal cut-out, but
something more intelligent ("if water's been continually flowing for more
than x minutes then shut the whole system down") would be even nicer...

I'm not sure if there's a cheap, reliable way of getting hold of a flow
sensor though (not something to measure rate of flow, just something to
detect if water is moving at all)


Flow switches are cheap as chips.

Farnell from £7.21 + VAT http://preview.tinyurl.com/38qjqt3

Use the diagrams from the last page here if you need to increase the
current switching capabitity: -
http://www.diyfaq.org.uk/docs/Sundia...%20Edition.pdf