When you switch it on, watch the breaker trip. Does it slowly move to off? That is a lazy breaker and needs replacing. People use breakers as switches and they are not made for that, so they wear out.
If the breaker snaps straight to off, you have a short to earth. Look for water around the electrics particularly at the pump.
If you can't see anything obvious, call out a pool electrician to diagnose and fix.
There are other ideas on the link.
https://www.google.com/search?q=pentair+pool+heater+trips+breaker
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I am thinking that model number might be suspect as my searches aren't finding that. 'Orca' is the model, 'Arctic Spas' is the maker. There are manuals and information in the lower link, but I think this is your manual for the Orca model.
limited info --one if the internal bladders/cell is damaged no fix keep twist seal lubed to prevent air/water leak and can still use until another cell pops
If it is new personally I would return it for an new that works,
I would not try to fix it. As I tell vendors or stores I pay what I want and I want what i pay for, nothing more.
