I need some help. I have a 2002 Hot Springs Vanguard Tub with a 20 and 30 amp GFCI circuit. I just refilled my tub and when I flip the 30 amp breaker with my 20 amp also on, it trips. It will run without the 20 amp on. I reset the high temp limit on the heater element. I have attempted to prime the tub which seems to work because it runs at full power, I am looking for some advice...

Your Heater's probably groundfaulting or the heater circuit board is damaged. Call your local dealer or we can help if you feel comfortable investigating it yourself.