Heater will get up to about 96 degrees and pump 1 will stop. Let it rest 10 minutes and I can heat it a few more degrees. At 99 it stops. That's about the high end limit of heating the tub.

The powerpack is a DCS. It's mounted on the top of the tub.
The system runs on a 220V breaker.
It has two 7.5 hp pumps.

Unfortunatly I'm not spa savvy so that's about all I can tell you.

Forgot to put, spa maker is Emerald Spa. It is 4 years old.