You can change the fuse in your hot tub through the following steps:
Turn off the power to your hot tub at the circuit breaker box.
Remove the hot tub side panel and the control box cover.
Refer to the circuit diagram to locate the fuse on the control panel. The circuit diagram usually comes with the owner’s manual provided by your manufacturer. At other times, it's glued to the back of the control box cover.
Once you find the fuse, pull it out of the fuse clips. If it won’t come out, gently pry it out using a small screwdriver. Be sure not to drop the fuse since it can get lost amidst all the wires and panels in the control box.
Perform a continuity check on the old fuse to see if it’s blown or defective, in which case you’ll need to replace it with a new one. If the fuse appears to be working perfectly, the problem may not be with the fuse and you may need to call in an expert to help you determine the issue.
Perform a continuity check on the new fuse to ensure that it’s in perfect working condition.
Insert the new fuse into the fuse clips.
Turn on power to the hot tub. If the fuse is installed correctly, then all should work properly now.
9. Turn off the power and replace the control box cover and side panel.