Trying to figure out exactly what is wrong with the hot tub.

The unit will turn on and will run for a period of time (with one pump it seems to run for a few hours before tripping off, with both pumps on, it seems to trip out sooner). When it trips, the LED heat indicator on the top side flashes pretty rapidly. Searching online indicates this should be a Sn1 or Sn3 indication (I could be wrong on that).

The other unusual condition is that when the system runs and is calling for heat (heat on LED top side on), there is power to the heater element, but the heater tube does not get warm to the touch (the stainless holder behind the controller box), so I don't think it is working. I did shot the heater element when it was in place (e.g. breaker to spa open but did not disconnect any wires) and got a reading of ~10 ohms, which appears to be what is expected.

Would a bad heater lead to the system running for a time and then tripping out with the flashing LED?