Hayward AquaRite 900 "Inspect Cell" Light: Cleaning, Scale, and Cell Replacement

What the "Inspect Cell" Light Actually Means

The AquaRite 900 tracks both runtime hours and how effectively the cell converts current into chlorine. After a set number of operating hours the controller will start flashing the Inspect Cell LED to remind you to physically inspect the cell. It will also light this indicator if it detects reduced performance that suggests scale, debris, or wear.

When the light is flashing you are in reminder or mild warning territory. When it stays solid, the controller considers the cell efficiency to be very low and may stop generating entirely. Pressing and holding the diagnostic button after a successful inspection resets the reminder timer.

Step-by-Step Troubleshooting

Owner-Level Checks

Check the LED state

• Flashing suggests it is time to inspect or that performance is somewhat reduced.
• Solid suggests significant loss of performance and possible shutdown.

Inspect the cell

1. Turn off power at the breaker.
2. Loosen the unions by hand and remove the cell from the plumbing.
3. Look through the clear body at the plates. Light dusting is normal, thick crust or flakes are not.
4. Remove any visible debris caught between plates.

Clean with a hose and tool if lightly scaled

1. Use a high pressure garden hose to flush between plates.
2. If needed, use a plastic or wooden tool to gently scrape soft deposits. Do not use metal tools that can damage the coating.

Reinstall and reset the reminder

1. Reinstall the cell, tighten unions by hand, and restore power.
2. Run the system and confirm there are no leaks.
3. Hold the diagnostic button for about three seconds until the Inspect Cell light clears to reset the runtime reminder.

Tech-Level Checks

If the light is solid or comes back quickly:

Perform a full acid wash

1. Mix a mild acid solution in a clean plastic container. Use a ratio around four parts water to one part muriatic acid.
2. Place the cell in the container so only the plate area is submerged. Keep the cable end dry.
3. Let it soak for a few minutes until bubbling subsides, then rinse thoroughly with a hose.
4. Repeat only if needed. Excessive acid cleaning shortens cell life.

Confirm water chemistry

High calcium, high pH, and high alkalinity all drive scale. Check and correct these to the recommended ranges so the cell does not quickly re-scale.

Evaluate cell age and replacement

• Most cells last roughly three to seven years depending on chemistry, runtime, and luck.
• If the cell is clean and chemistry is good but the Inspect Cell light keeps coming back solid, it is likely time for a new cell.
• Use diagnostics to check cell current. Abnormally low current at correct salt and voltage is a sign of end of life.

Common Parts That Fix This Problem

• Muriatic acid and a plastic bucket for cleaning
• Replacement Turbo Cell (TCELL925 or TCELL940) when the original is worn out
• Chemicals to correct pH, alkalinity, and calcium if water balance is driving scale

Model-Specific Notes

• The AquaRite 900 manual specifies holding the diagnostic button for a few seconds to reset the Inspect Cell timer after cleaning.
• Different cell models have different lifespans. A t-15 cell may last longer than a t-3 cell in the same pool because it runs at lower duty cycles.

How to Prevent Repeat Inspect Cell Warnings

• Keep calcium hardness, pH, and alkalinity in the recommended ranges.
• Inspect and clean the cell once or twice per season even if the light is not on.
• Do not over-chlorinate. Running at maximum output constantly accelerates wear.
• Keep records of cell age and runtime so you can anticipate replacement.