Help troubleshooting SqlException: Timeout expired on connection, in a non-load situation

Question

I have a server hosting a website of mine that has almost zero-traffic.
A few people (< 20) enter the site every day, and a few RSS readers are subscribed to some fee

Answer 1

I would compare the timestamp of the timeout with the execution time of your nightly backup. If they coincide, you could set your RSS feed to be static for that time.

Another thing to try (even though it isn't exactly an answer) is to immediately run sp_who when you get a timeout exception. It won't catch everything (the offending process could be done by the time you run this) but you may get lucky.

You can also fire up SQL Profiler when you head home for the night and step through the activity the next morning if you see the error again. Just be sure to not run it from the server itself (I'm pretty sure it reminds you of this when it starts).

EDIT: Addressing your update.

Is EF updating/creating its cache? It could explain the abundance of queries at one time and why no queries had database hits later.

Other than that, it appears you have a heisenbug. The only thing I can think for you to add is a lot more logging (to a file or the event log).