A few times in the last year, I've woken up to no hot water.
In checking the TM-1, there was no power to the remote/display.

I discovered that one of the 5A fuses on the circuit board was blown.

Replacing the fuse makes everything fine for at least a few months (like I said, this has happened 3 times in 12 months).

On one occasion, we had a power outage, so maybe their was a surge when the power came back on, but usually if the power goes out, the unit stays off even when the pwoer comes back on, so I doubt that is it.

Has anyone else had this happen? My unit is probalby 4 years old now and I'm sure it is out of warranty (though I plan to check).

whatever it is doesn't happen all the time as a new fuse works for quite a while.