Hayward AquaRite T-Cell-15 Replacement: How to Diagnose a Dead Cell and Swap It Out — A South Florida Pool Pro's Guide

The most likely fix when an AquaRite is not making chlorine:the T-Cell-15 is at end-of-life. Confirm with the AquaRite's diagnostic display: if instant salt reads well below your lab salinity, cell voltage is high, and amps are low, the plates have lost their coating. Acid-wash first — scale mimics dead-cell symptoms. If the diagnostic still fails after a clean cell, replace it. The job is a 45-minute swap with two unions and a cable connector.

Most common symptoms

• Pool chlorine reads zero despite the AquaRite displaying generation.
• Instant salt reads 500–1,500 ppm below actual lab salinity.
• Inspect Cell light is on (or has been on for a long time).
• AquaRite shows “No Flow” intermittently with a working pump — sticky flow switch, not always the cell.
• Cell shell is discolored, plates look pitted or eroded when inspected.

Diagnostic walkthrough

1. Verify actual salinity at a pool store. Don't trust the AquaRite's number until you know what the water actually is. Target is 3,200 ppm.
2. Run the AquaRite diagnostic. Hold the Diagnostic button. Cycle through: instant salt, cell voltage, cell amps, water temp, desired output, percentage output. In our field experience on current AquaRite firmware, a healthy cell at 3,200 ppm and 75°F shows cell voltage in the low-to-mid 20-volt range and amps in the 5–6 A range. Maxed-out voltage with low amps points toward a worn cell. Confirm the expected diagnostic ranges against your AquaRite's service manual revision.
3. Pull the cell, inspect, acid-wash if scaled. Hard South Florida water lays scale on the plates within a year. A 4:1 dilution (four parts water to one part muriatic acid) bath, plates submerged ~10 minutes, restores most cells that just look bad. Always pour acid into water, never water into acid; wear chemical splash goggles, gloves, and long sleeves; work outdoors; and never mix with chlorine products. Hayward's cell-cleaning instructions in the AquaRite manual are the authoritative reference for ratio and dwell time. Re-run the diagnostic afterward.
4. If diagnostics still fail after acid wash, the cell is dead. The titanium plates lose their ruthenium coating over time. No cleaning brings that back.

Step-by-step replacement

1. Power down the pump at the timer or controller. Power down the AquaRite at the breaker.
2. Close suction and return valves to isolate the cell housing.
3. Unscrew the two unions on the cell housing. Have a towel ready — about a cup of water comes out.
4. Disconnect the cell cable at the AquaRite end (or at the cell itself if it has a quick-connect).
5. Lift the old cell out. Note flow direction arrow.
6. Install the new cell with the same flow direction. Replace the union o-rings — never reuse old ones on a salt cell. They harden and weep.
7. Reconnect the cable. Open the valves. Prime the pump.
8. Restore power. Run the AquaRite diagnostic. Voltage should be 22–26 V, amps 5–6 A. New cell — clear the Inspect Cell timer per the AquaRite manual sequence.

South Florida-specific failure modes

• Calcium scale. Hard fill-water on the southeast coast lays scale on cell plates 2–3 times faster than soft inland water. Acid-wash quarterly on coastal pools.
• Salt-air corrosion on the cell cable connector. The plug at the AquaRite head corrodes. Dielectric grease at install. Replace the cable if green corrosion is visible.
• Chlorine demand from heat and UV. Florida pools demand more chlorine than northern pools, which means more cell hours per year, which means shorter cell life. 4–5 years is normal here vs. 7–10 in mild climates.

When it's time to replace

If the cell has 8,000+ run hours, has been acid-washed twice this year, and the diagnostic still fails — replace. There is no rebuilding a cell. See our salt chlorine generators primer for the broader system context, and our coastal salt-air guide for why coastal cells age faster.

When to call a pro

If you have never pulled a cell, the AquaRite breaker scares you, or your pad has a tangled wiring nest from a past renovation — call. In Florida, residential pool repair work is regulated by the DBPR (RP / CPC license categories). A pool equipment repair visit gets the cell tested, the salinity verified, and a flat-rate quote in writing before any work happens.

FAQ

How do I know my T-Cell-15 is dead? Diagnostic shows high voltage, low amps, and instant salt that reads well below lab salinity, even after acid wash.

How long should a T-Cell-15 last?Rated 10,000 hours; typically 4–7 years in Florida, 3–5 on the coast.

Can I replace it myself? Yes if you can isolate the line and turn off two unions. Power down both pump and AquaRite first.

What does Inspect Cell mean? A scheduled 500-hour reminder, not a fault. Pull, inspect, clear.

What does installed replacement cost?[VERIFY] — pricing varies by supplier and season. Get a written flat-rate quote.