Now, does it trip off?
If not, shut the power off and plug in the pump that connects to the heater plumbing.
Turn the power on. If it trips, bad motor. If it stays on, repeat this procedure for each component except the heater, turning the power off in between each item you plug in.
If the tub is running, turn the power off and reconnect the heater wires. Turn the power back on.
If it trips the breaker, bad heater.
Please respond when you have tried this. It is the fastest method to diagnosis a gfci tripping.
Okay, that answers that question.
Now, lets talk about the blower and what options you have.
Blowers trip the gfci usually because water got into the blower. This is not uncommon if the tub was overflowed filling it or if you had a lot of people in it just prior the gfci tripping.. If the blower was not especially noisy lately, that may be the case.
If that happened, give it a week and plug it back in. If it still trips, replace the blower.
If water is not the cause, then nesting critters sometimes make their home in them if unused for a while. If that is the case, replace the blower.
Sometimes they go bad. Replace the blower.
I know you see a pattern...replace the blower. That is most likely the solution, however, I would leave it unplugged for a week and try it again. If it still trips..you guessed it...replace the blower.
The cause was found, and with a little luck the blower may work again.
If you would like some links to sources, let me know if you are going to replace it. I will be happy to follow up with you and do that.
Have I answered your question thoroughly?
Thank you and have a great day!