I have a 2004 cal spa 4000. The heater trips my GFCI circuit breaker. Resistance at heater is 10 ohms. 220 volts across heater leads. Infinity (open) between leads and ground. Tub runs great with the heater leads disconnected. If I touch the either heater lead to its terminal while the tub is operating it trip's C/B immediatly. Thanks for any help in advance.