How to Remove and Replace the Spa Boy Cell

The Spa Boy cell (the Onzen electrode) makes the sanitizer from your salt water.

We recommend replacing it once a year.

You can do this with the tub empty or completely full.

All you need is a regular Phillips screwdriver and a new Onzen Electrode Salt Cell Cartridge (5 Plate).

1. Turn off the breaker

Flip the breaker for the spa off before you start.

2. Unthread the cell housing from the spa

Unthread the electrode and its housing completely out of the spa wall.

Pull it up and out of the water.

If your tub has water in it, keep the housing completely dry.

3. Loosen the set screw

There's one set screw on the housing.

Loosen it completely with a Phillips screwdriver.

4. Twist out the old electrode

Twist the old electrode out of the housing and pull it completely out.

Keep the inside of the housing completely dry.

5. Thread in the new electrode

Thread the new electrode into the housing.

Make sure it hits the stop, so the set screw can line up with its spot on the inside.

Then tighten the set screw.

6. Put the housing back in the spa

Feed the cord back into the niche inside the tub.

Thread the whole assembly back into the spa wall.

7. Turn the power back on

If you drained the tub, fill it.

Flip the breaker back on, and you're done.

Questions?

Give us a call at 801-483-1001 and we'll walk you through it.

Video: How to Replace an Onzen Electrode

Watch on YouTube: How to Replace an Onzen Electrode

Oct 29, 2026

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