Hayward AquaRite 900 Troubleshooting Guide: Lights, Messages, and Common Problems
The Hayward AquaRite 900 series (AQR925, AQR940) is a salt chlorine generator that lives on the equipment pad and quietly turns dissolved salt into free chlorine. When it is happy you get steady chlorination with minimal chemical handling. When it is not, you get cryptic lights, odd salt readings, or a pool that will not hold chlorine.
This guide is written for working pool techs and serious DIY owners. Assume you are standing in front of the box with the door open, the pump running, and your test kit nearby. The goal is simple: read the lights, interpret the numbers, and decide what to fix next.
You will find quick meanings for each indicator, a plain language explanation of how the AquaRite 900 actually decides to generate, and direct links into deeper troubleshooting articles for each major symptom.
Quick Reference: AquaRite 900 Lights and Common Symptoms
Power LED Off
Meaning: No incoming power or blown fuse.
Next step: Check breaker, timer output, line voltage and fuse in the control box.
View detailed guide →"No Flow" Light On
Meaning: Flow switch not seeing enough movement.
Next step: Pump on, valves open, filter pressure, straight pipe before flow switch.
View detailed guide →"Check Salt" Light
Meaning: Salt level is low or borderline, production may be reduced or stopped.
Next step: Measure salt with independent test, compare to display, confirm correct cell type.
View detailed guide →"High Salt" Light
Meaning: Salt is above the acceptable range, system has shut down.
Next step: Verify salinity with test kit before draining any water.
View detailed guide →"Inspect Cell" Light
Meaning: Cell performance has dropped or it is time for scheduled inspection.
Next step: Pull and inspect cell for scale or debris, then reset timer if clean.
View detailed guide →"Generating" Light Off
Meaning: System is not driving the cell, no chlorine production.
Next step: Check main switch position, desired output, salt range, flow, temperature.
View detailed guide →Wrong Salt Reading
Meaning: Display shows decimal value or doesn't match test kit.
Next step: Check diagnostic menu, instant salinity, ppm vs g/L, cell type setting.
View detailed guide →Pool Has Low Chlorine
Meaning: Output not matching demand even though Gen light is on.
Next step: Check output percentage, pump runtime, stabilizer level, bather load, cell condition.
View detailed guide →"Remotely Controlled" Light
Meaning: Automation system has taken over control.
Next step: Check automation mode, schedules and output setting on controller.
View detailed guide →Turbo Cell Type Mismatch
Meaning: Controller t code doesn't match installed cell.
Next step: Compare model on cell label to t setting in diagnostics.
View detailed guide →How The AquaRite 900 Actually Works (Quick Overview)
At a high level the AquaRite 900 is just four main pieces working together:
- A control box with transformer, circuit board, fuse, and front panel
- A Turbo Cell installed in the return line, where electrolysis happens
- A flow switch that tells the control when water is actually moving
- Sensors and firmware that estimate water temperature and salt level
When the filter pump is running and water is moving past the flow switch, the control checks three things before it sends power to the cell:
- Salt level must be within its allowed band. The system targets roughly 2700 to 3400 parts per million, with performance centered near 3200.
- Water temperature must not be too cold or too hot. If it is out of range the unit will flash the Generating light and stop production.
- The main switch must be in Auto or Super Chlorinate and the desired output setting must be above zero, unless automation is running the show.
Critical Water Chemistry
- Free chlorine: Around 1 to 3 ppm for most pools
- pH: Around 7.2 to 7.8
- Total alkalinity: Around 80 to 120 ppm
- Stabilizer: Around 30 to 50 ppm
- Calcium hardness: Around 200 to 400 ppm
- Salt: Around 2700 to 3400 ppm
Keep those in range and most AquaRite headaches disappear.
Most Common Problems
1. Panel Dead, No Power LED
- Breaker off or timer not feeding power to the control
- Miswired line and load or wrong voltage configuration
- Blown internal mini fuse
- Failed transformer or main board
2. "No Flow" Light On or Flashing
- Pump off, valves closed, or filter extremely dirty
- Flow switch installed backwards or without enough straight pipe
- Flow switch cable unplugged or damaged
- Weak circulation on low speed that never satisfies the switch
3. "Check Salt" Light Flashing or Solid
- Real salt level has dropped below target band from splash out, backwashing, or refills
- Cell type set wrong so control is miscalculating salt
- Sensor reading skewed by scaled or aging cell
- Average salt value not updated after adding salt
4. "High Salt" Light On
- Too much salt added, especially if pool volume was misestimated
- Heavy winter dilution changes or partial drains not accounted for
- Wrong Turbo Cell type or wiring problems causing misreading
5. "Inspect Cell" Light Flashing or Solid
- Scheduled service timer reached roughly five hundred hours of runtime
- Visible scale on plates from high calcium or high pH
- Debris or dog hair packed between plates
- Cell coating worn out after years of use
Basic Diagnostic Checklist Before You Dive Deeper
Confirm power and pump operation: Verify filter pump is running when you expect chlorination. Check breaker feeding the AquaRite. Confirm timer or automation is sending power during your test.
Check the obvious hydraulics: Look at return jets for strong flow. Check filter pressure against clean baseline and backwash if high. Make sure valves are not throttled so flow through cell is weak.
Read the front panel indicators: Note which LEDs are on, off, flashing, or changing. Look at the default salt reading and whether it is in expected range.
Use the diagnostic button: Step through pool temperature, cell voltage, cell current, output percentage, instant salinity, product code, software revision, and cell type. Write values down before changing anything.
Verify chemistry with test kit: Check free chlorine, pH, alkalinity, stabilizer, calcium hardness, and salt. Do not trust only the built in salt reading if you are about to drain or add a lot of salt.
Inspect the cell: With power off, remove cell and look between plates for deposits or debris. If heavy scale is present, follow cleaning procedure and recheck output.
Confirm Turbo Cell type: Compare cell label to the t code in diagnostics. Correct any mismatch before chasing phantom salt problems.
When To Stop And Call A Professional
Some work on an AquaRite 900 is owner friendly. Some of it is not. Stop and bring in a qualified tech if:
- You need to open the electrical compartment and you are not comfortable working around 120 or 240 volt circuits
- You suspect the transformer or main circuit board has failed
- Wiring needs to be changed between 120 and 240 volt setups
- Salt corrections require large drain and refill decisions you are not confident making
- The cell has been cleaned correctly and still shows low current or persistent Inspect Cell warnings
Use only genuine Hayward replacement cells and fuses. Mixing in non listed parts or modifying wiring away from the diagrams is asking for nuisance failures and warranty fights.
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