First Step is to determine what you have and what you need.

1. Incoming voltage. Whether 120vac or 240vac, it has to be GFCI protected. If you are running on 120vac through a cord, it likely has a GFCI on the cord or the outlet. Usually you can continue to use that cord or outlet. If you are operating on 240vac, you have to determine that your electrical source is GFCI protected. There are several designs for this but most common is a gfci protected breaker at the electrical panel or subpanel. It has a "test" button on the gfci. But whatever method you use, you MUST this for both safety and national code. If you don't know, you can have a licensed electrician determine this for you.

2. What equipment you have and the voltage the equipment runs on. If your electrician source is 120vac, all your equipment will be the same. If your electrical source is 240vac, your individual pieces of equipment can be 120v OR 240v. You have to read the label on the equipment.

3. List WHAT equipment you have such as pump(s), air blower, ozonator, and mood lights.

Second Step is to determine what you want to do and match the retrokit to fit.

1. You can just replace the old with the same new control box and keep it simple. (when available)

2.  You may want to change or add features or upgrade incoming power.

3. Change from mechanical system or one lacking digital topside control.

Now you are ready to figure out your options. and see what's available and cost.

How hard can it be? Click Here to see how I installed a retrofit into a Jacuzzi Alexa Spa.