Cal Spa marked 9-2-99 21268
Model PS-4 Volts 220 Amps Freq. 60Hz
1 phase, 3 wire & Ground
Single GFCI on panel.
Flow through Stainless steel heater. (don't know length or heater model type but would like to)

Unit sat for 2-3 years. Drained, cleaned, primed pump, bled air.
1. Full power jets work fine, no problems and will keep running without popping the GFCI.

2. Unit can be in either timer or freeze protect. When circulation / heating is on, it runs for 1 to 1 1/2 minutes and the GFCI pops. There is a heater reset button and heater light on the panel cover. The reset is not tripped. The heater light is not lit at any time.

So my guess is the heater BUT thats why I'm here first. Will try disconnecting the ozone, heater and other plugs at the bottom of the control box tomorrow. Looking for information on what else to check on the heater / control box.... before tearing into things.

Until I remove the control box I cannot see any markings on the heater. Does anyone have a size and power standard for this make (Cal Spa) and model?

Thanks in advance for all assistance.