Hi All
Thanks for the input. That sensaphone gizmo is pretty much what I'd envisioned. And, Eagle, the home is down in MA. But, I think I'll give his oil supplier a call and see if they offer the same service.
SAMIAM, that's a heck of a good idea; I'm ashamed that my Dad and I didn't think of it. (He was a plumber, and I grew up helping him!

) The main supply valve is getting shut off next time I go down there, even with a monitoring system.
If anyone knows of any additional units similar to the sensaphone, I'd be very happy to hear about them.
Thanks again,
Silver Duck