Why Your Saltwater Chlorinator May Stop Working

A saltwater chlorinator (SWCG) is a fantastic device that brings automation and convenience to pool ownership. However, like any piece of sophisticated equipment, it can encounter issues and stop working. Seeing a red error light or noticing your chlorine levels have plummeted can be alarming. The good news is that most SWCG failures are caused by a handful of common, diagnosable, and often fixable problems.

This troubleshooting guide will provide a systematic, step-by-step approach to help you identify why your saltwater chlorinator has stopped working. By checking these items in order, you can solve the majority of issues yourself without an expensive service call.

Step 1: Check the Most Basic Functions

Before diving into the system itself, always rule out the simple external factors. It's surprising how often one of these is the culprit.

• Is there power? Check your home's circuit breaker to ensure the breaker for your pool equipment hasn't tripped. Look at the SWCG's control panel—are any lights on at all? If not, it's a power issue.
• Is the pump running? Your SWCG is wired to only operate when the pool pump is running and water is flowing. If your pump is off, the chlorinator will be off too. Ensure your pump's timer is set correctly and the pump is functioning.
• Is the filter clean? A very dirty filter can reduce water flow so much that it triggers the SWCG's flow sensor to shut the system off. If you haven't cleaned your filter recently, now is the time.
• Is the pump basket empty? A pump basket full of leaves and debris will also restrict water flow. Turn off the pump and clean it out.

Step 2: Read the "Error Code" - What is the System Telling You?

Your SWCG's control panel is your primary diagnostic tool. The indicator lights are there to tell you exactly what's wrong. Here are the most common error lights and what they mean:

"No Flow" or "Flow" Light (Often Flashing or Red)

This is one of the most common errors. It means the system's flow switch is not detecting adequate water movement, and it has shut down to protect itself.Causes & Solutions:

• Pump is off: The simplest cause. Make sure the pump is running.
• Dirty Filter/Baskets: As mentioned above, clean your filter and all skimmer/pump baskets to improve flow.
• Incorrect Valve Settings: Ensure all your valves are in the correct position for normal operation and not partially closed or set to a feature like a spa drain.
• Faulty Flow Switch: The flow switch itself can fail or get stuck. It may need to be cleaned or replaced.

"Low Salt" or "Check Salt" Light

The system believes the salt concentration is too low to produce chlorine efficiently.Causes & Solutions:

• The Salt is Actually Low: This is the first thing to check. Use an independent digital tester or drop kit to get an accurate reading. If it's low, use our Pool Salt Calculator to determine how much salt to add.
• Dirty Salt Cell: This is a very common cause. Calcium scaling on the cell plates can trick the system into thinking the salt is low. Remove and inspect the cell; clean it if necessary.
• Cold Water: Most SWCGs will stop working and may show a "Low Salt" error when water temperature drops below 50-60°F (10-15°C). This is normal. The system will resume when the water warms up.

"High Salt" or "High Salinity" Light

The system detects that the salt level is dangerously high and has shut down to prevent damage.Causes & Solutions:

• You Added Too Much Salt: Verify with an independent test kit. The only way to fix this is to partially drain your pool and refill with fresh water to dilute the salt concentration.
• Electrical Issue or Faulty Sensor: In rare cases, this can be caused by a fault in the control board or cell, giving a false high reading.

"Inspect Cell" or "Clean Cell" Light

This is a maintenance reminder, typically triggered after a set number of operating hours (e.g., 500 hours).Causes & Solutions:

• It's Time for Inspection: The light is doing its job. Turn off the power, remove the cell, and visually inspect it for calcium buildup. Clean it if necessary using our cell cleaning guide.
• Reset the Light: After cleaning and reinstalling, you must reset the indicator light. The method varies by brand but usually involves holding down a diagnostic button for several seconds. Check your manual.

Step 3: What If There Are No Error Lights, But Still No Chlorine?

This can be the most confusing scenario. The system seems to be working, but your test kit shows zero free chlorine.

1. Check the Chlorine Output Setting

Ensure the output percentage on your control panel is set high enough. If it's set to 10% or 20%, it may not be able to keep up with demand. Try turning it up to 100% for 24 hours and see if the chlorine level rises.

2. Check Your Stabilizer (CYA) Level

If your pool's Cyanuric Acid (stabilizer) level is near zero, the sun will destroy the chlorine as fast as your cell can produce it. For a saltwater pool, your CYA should be in the 60-80 ppm range. Use our CYA Calculator to make adjustments.

3. Consider High Chlorine Demand

After a very heavy rain, a large pool party, or if you have a lot of leaves and organic debris, the chlorine demand of the pool can temporarily exceed the production capacity of your cell. In this case, you may need to manually shock the pool with liquid chlorine or cal-hypo to help it catch up.

4. Your Salt Cell is at the End of its Life

If you've checked everything above and your cell is clean, but it still won't produce chlorine, it's very likely that the cell is simply worn out. Salt cells have a finite lifespan of 3-7 years. If yours is in that age range, it's probably time for a replacement. Our guide on replacing vs. cleaning can help you make the final call.

By following these diagnostic steps, you can methodically identify the root cause of your chlorinator problem and take the correct action to get your system back online and your pool water sparkling again.