The house we bought in July 2003 has a Discovery Spa. It has been working fine. Suddenly, we started tripping breakers. It will run from minutes to hours and then trip the 50 amp breaker at the fuse box. The pump works. The heater workss. I can find no obvious problems. Any ideas?????

You didn't say if it was a 50 amp GFCI breaker, (a breaker with a little test button on it), so I'm assuming for now it's just standard.

You need to feel the circuit breaker for it's temperature when it's running, and/or after it trips. If it's excessively hot, then the problem is usually the screws that hold down the wires in the breaker are loose, there's corrosion setting in, or other things that will create resistance in the connection. This resistance creates the heat that will cause the breaker to trip.

If it's been doing it a lot, and the connection is the source of the problem, then most likely your breaker is heat damaged and you'll need to replace it as well as check the connecting wire for heat damage.

Here's some classic examples of this problem:
http://spasupport.com/electrical/main/burnedwires.html

Thanks and let us know how it turns out.

You hit the nail right on the head. Thank you so much. I felt the breaker and sure enough, it was hot. further investigation found loose screws. The wires just pulled out. A little tightening of the screws and we're back to soaking. Thanks again.