Is it OK to have 2 baths on the same circuit????

Have you done a VOM test on the house lines to the bath from the circuit breaker box? This is important, without the GFI in place, just the bare wire test? If you have voltage from the box to the Bath wires, then your power is correct and the attached outlet needs to be checked for continuity. If no power to the bath from the box, the circuit breaker may be bad, or tripped.

PROBABLY TIE INTO A GFI CIRCUIT SEEING IT IS IN A BATH AREA

You can get 2 types of Jacuzzi baths, 1 with just a pump which just jets the water via a small pump or 1 with the pump and elements that heats the water aswell as pumps the water through the jets. Because the 1 with the elements has a higher amp rating you need to run a cable from your distribution board to your bath but the 1 without the elements you will be able to tap off the nearest socket to the bath, you will be coming from your socket to a fused spur outlet, it would be better to get a switched fused spur outlet as you will be able to isolate the bath when not in use just by switching off the switch. from the spur outlet you will be wiring it into your motor on the bath, it should say the rating of the pump in amps on the tally plate of the motor or on the manual. For example if it says the motor draws 2 amps you will be putting a 3 amp fuse into your spur outlet so if there is a fault with the motor the fuse will blow instead of tripping the whole socket circuit. All jucuzzi baths has to be connected to the RCD side of your distribution board. If you are tapping off a socket don't worry about the RCD because all sockets should be on the RCD anyway, to check that the socket is connected to the RCD plug something into the socket you are tapping off of and press the test button on the RCD, the RCD should trip and while this is tripped check the lamp or whatever you plugged in shoud be off. The Fused spur should be fitted outside of the bathroom.

It sounds as if the relay is not latching on the circuit board for that tub. You probably want to have a Jacuzzi service tech come and take a look at it.

Obviously a circuit overload, or short. Was it working ok, before, and have you by chance added anything to the circuit that supplies power to the tub?

If it is droped in the bath, DON'T TURN IT ON! Let it thouroughly dry for 2 days before attempting to turn on this device. Otherwise the circuits will burn out

These usually have a larger drain line than a shower or bath. If you are draining into a smaller drain then there will be a considerable amount of backing up. This is not a good idea. hope this helps. Good luck.

remove box then put through wall put it back on other side

Air bath tubs have a preset time limit. it could be that it reached that limit. Especially if the lights are still lit up on the control.