Hi , I am in the process of installing a whirlpool tub in my bathroom and I need to run a dedicated circuit to it. I have an unused 220 outlet in my garage that I was hoping to split ad run a line to the whirlpool from. The tub pump is rated at 10.5 amps and there is no inline heater . I was trying
To figure out what I needed to do in the breaker box so the circuit is properly protected. I was going to turn the 22o outlet for the dryer into a 110 and run a 110 line from the same outlet under my house to the bathroom, But I need to split the circuit at the box and I need to know what type of breaker do I replace it with
Thanks

Remove the existing double breaker, if the existing dryer cable is a 2-conductor (3-wire) cable, connect the white wire to the neutral buss connect the black wire to the new single breaker. If the dryer circuit is a 3-conductor (4-wire) cable, cap off the red wire. By same outlet under the house I assume you really mean a box. Connect wiring of correct size for tub. You must have a means of disconnect at the tub. That can be a switch with the tub hard wired or it can be a receptacle with a cord and plug. If it is wired cord and plug you can use a GFI receptacle. If it is hardwired you will have to use a GFCI breaker.
Size the breaker and wiring according to the requirements of the tub.