I have an Amish Country Eden spa, 240V, installed in 2000. Lately, it has been going to a condition labeled on the display as "O" from which it is completely unresponsive and requires a main circuit breaker reset. The manual doesn't list "O" and it does not restart when the temp drops by as much as 30 degrees.

Then last night I was in it and it repeatedly went from its set temp (100), 2 seconds of the secondary pump, showed the "O", and then went back to the set temp.

I assume it's a control problem. Do these symptoms sound familiar to anyone? And, if so, what's my course of action?

Thanks, Rob