Best Practices for Troubleshooting Salt Chlorine Generators

Problems with your Pool’s Salt System May Require Immediate Attention

Salt chlorine generators are a key component of swimming pool systems. They convert salt into chlorine to provide continuous sanitization of a pool’s water. Like any pool equipment, salt chlorine generators can sometimes encounter issues that require troubleshooting and maintenance. In this comprehensive guide, we will explore common problems salt chlorine generators can have and provide tips and solutions to help you resolve them. Whether you're experiencing low chlorine levels, error codes on the display screen, or other issues, we've got you covered with practical troubleshooting steps. By understanding the potential problems with salt chlorine generators and their solutions, you can keep your unit running smoothly and ensure optimal pool water quality.

For a full discussion of all things saltwater chlorine generators, check out our comprehensive guide.

1. The Reasons Why A Saltwater Chlorinator Stops Working

A salt chlorine generator is ultimately a simple device - it is designed to send power from its control module, to its cell, through the water, and then back to the control module, where it measures how this process is working.

When a chlorine generator is unable to do this, there is almost always going to be one of the following typical reasons that force it to stop generating chlorine correctly. When this happens, a chlorine generator will trigger a warning light, error message, or alert. This will most often be a “low salt” or “clean cell” message. If you are not seeing a system warning, skip ahead to the next section.

2. If You Are Seeing Warning Lights On Chlorine Generator

Low Salt In The Pool

Most pool owners will encounter this at a certain point. Insufficient salt levels can impact the salt chlorine generator's ability to produce chlorine. Check to see if the low salt light on your pool’s chlorinator is illuminated and test the salt levels using testing strips or kits to ensure they are within the recommended range specified by the manufacturer. If the salt level is low, add the necessary amount of pool-grade salt to reach the optimal concentration.

Dirty Or Clogged Salt Cell (Mineral Scaling)

Most pool owners will also encounter this at a certain point. Over time, mineral scaling can build up on the salt cell, reducing its efficiency and hindering chlorine production. Regularly inspect the salt cell; if you see mineral scaling (or other debris), clean the cell thoroughly according to the manufacturer's guidelines to remove any mineral deposits. Sometimes, when there is mineral scaling in the cell, it can also cause your chlorine generator to think there is not enough salt in the cell. If you’ve independently measured a good salt level and your system thinks there is low salt, this is a common indication that the cell needs to be cleaned. Many times it can be hard to see inside your cell, so if you’ve checked your salt level and are still getting a low salt or salt cell error, just go ahead and clean the cell as the next step. If you see “fizzing” when you clean the cell, you’ll know there is mineral scaling to dissolve.

Air In The Salt Cell

In order to pass along the expected amount of power through the cell, the cell needs to be 100% filled with water so that its titanium plates are completely covered. A salt cell may develop an “air gap” where a pocket of air develops inside the cell if the pool system is sucking in air somewhere upstream. If this happens, it can essentially trick your system into thinking there is low salt or a dirty cell, since it becomes more difficult for the system to send power through the cell. This may occur due to a bad seal, loose fitting, cracked plumbing, low water level in the pool, improperly primed pump, or other similar reasons. You’ll need to inspect the pool system for these issues. Additionally, if using a variable speed pump, it can be possible that at its lowest RPM settings that the pump is not moving enough water to clear any air out of the cell. If your error seems to occur every day or overnight, but you can reset your salt system and it will work without error for the rest of the day (which means the salt level is good and the cell is fully clean), this is a tell-tale sign of air in the cell due to insufficient flow. In this case, incrementally raise the RPM of your pump's low speed setting. Often only small adjustments are required and you can still ensure very energy efficient operation of the pump while still providing correct water circulation.

Wrong “Cell Type” Setting On The Controls

In many cases, a chlorine generator model line uses one controller that can work with different size salt cells, and the controller has a setting on it that lets it work properly with each cell size. Sometimes this setting may inadvertently get changed, or you may purchase a larger salt cell down the road. When the “cell type” setting does not match the actual cell size being used by the controller, it will not work correctly and will cause the system to trigger an error. Many times this will be a low salt or high salt warning, because the system is sending power through the cell and finding that it is easier or harder to do this than expected. Consult your product manual to see if your chlorine generator has a cell type setting. Double check the manufacturer’s documentation to determine what cell type setting your system should have.

Low Water Temperatures

At very cold water temperatures, microorganisms have little chance to grow, which requires little to no chlorination. Additionally, electrolysis in very cold water can increase wear-and-tear on a salt cell. Some models will display a temperature alert, so you can know that the system is correctly adjusting its operation. In rare cases, or on some older models, cold water temperatures may contribute to a “low salt” or “clean cell” system indicator. If the water is cold and there are no other issues (low salt, scaling in cell), this issue may simply resolve itself. However, if a temperature warning occurs and the water is not actually cold, this may also indicate a more rare issue, that the system’s temperature sensor is damaged.

Bad Cable Connection

If the cable that goes between the controller and the cell is not getting a 100% connection or is damaged, this can make it harder to send power along and it is possible for this to cause a “low salt” or “clean cell” system indicator. Additionally, this may cause a safety issue! Be sure that the cable and its male and female connectors are clean and undamaged. Reconnect the cable, making sure its connectors are properly aligned and fully seated.

Salt Cell Needs Replacing (End Of Life)

The salt cell has a limited lifespan, typically ranging from 3 to 8 years depending on the model and usage. Be prepared ahead of time by knowing what to look for when your cell reaches the end of its lifespan. If you’ve had your system a number of years and your salt chlorine generator is triggering a “low salt” or “clean cell” system indicator, and you’ve checked all of the above troubleshooting and double-checked that the pool’s salinity level is good and the cell is thoroughly clean, it may be time to replace the salt cell.

Other less common system error issues:

Bad setup (incorrect wiring, not wired properly). Improper installation or wiring can cause issues with the salt chlorine generator's functionality. Ensure that the system is correctly installed and wired according to the manufacturer's instructions. If you're uncertain about the setup, consult a professional for assistance. If the controller is hooked up incorrectly (only receiving 120V when configured for 240V), the system may power on and the person installing the unit may walk away, but the system may provide no or erroneous readings and not send power to the cell in order to generate chlorine.

Issue with flow switch or sensor; "low flow" or "no flow" light is on. If the chlorine generator does not think the water is flowing, it will stop generating chlorine. If water is not flowing correctly, check for pump operation, high filter PSI, skimmer debris, or other blockages. A flow switch also might not be triggered properly if it is installed too closely to a plumbing elbow or other source of turbulent water. The flow switch can be checked if it is or is not functioning correctly by removing it and manually triggering it. You should always see a “no flow” error when the flow switch is not triggered, and you should always see the “no flow” indication go away when the flow switch is triggered. A malfunctioning flow switch should be replaced.

Control unit on the salt chlorine generator has electronics damage. Some newer models will provide a warning light or error if electronics damage is detected. For other models however, if your system is powering on and giving a warning light like any of those listed above (such as “low salt” or “clean cell”), and not of the above issues are the case, in extremely rare circumstances, it is possible that a damaged Faulty control units or electronic components can disrupt the operation of the salt chlorine generator. Based on experience, it is emphatically much more likely that a system with an electronics issue just doesn’t turn on, and almost always will be accompanied by physical damage which can be inspected for by a qualified individual. In any of these instances it is recommended to contact manufacturer tech support.

3. If There Are NOT Any Warning Lights On Chlorine Generator

If you are NOT seeing warning lights or alerts on your chlorine generator, but are seeing other signs that your chlorinator might not be working, these issues may be at play:

Tripped Power Or Control Module Not Receiving Power

Most chlorine generators have a built-in power protection mechanism (a fuse or a fuse reset / internal breaker). Make sure that the chlorine generator’s power protection mechanism is not tripped and thus causing the system to be inactive. Also make sure that the chlorine generator is not simply set to “off” on its controls. Check that the salt chlorine generator is plugged in and receiving power. Additionally, verify that no circuit breakers or GFI outlets which supply power to the chlorine generator have tripped. Reset any tripped breakers or outlets and ensure the unit is properly powered.

No Display Or Unresponsive Controls

It’s possible the controls are receiving power but another issue on the controls is preventing the system from operating properly. If the unit's screen and/or LED lights are partially lit, there may be a damaged display circuit board. If you are pressing a button, moving a switch, or turning a dial but the system does not respond, the system’s keypad or control circuit board may need to be replaced.

Overheated Electronics

While it's normal for electronics to feel warm to the touch, if the internal temperature of the electronics gets too hot for whatever reason, many electronics have a built-in temperature protection mechanism that may cause the system to temporarily turn off. If this is the case, wait an hour or two for the temperature of the unit to cool off. Older technology may encounter this more often than newer models. Ensure that your chlorine generator controls are not installed near a heater or heat source.

Damaged Electronics

If a local power surge occurs, or if an internal component fails, it is possible that electronics become damaged. Some newer models will provide a warning light or error if electronics damage is detected. If the unit does not come on after troubleshooting the previous issues, or if damage is visible (or you can smell it), an internal circuit board may need to be replaced.

Other Error Message

Some chlorine generator models have unique error codes or messages that only apply to their configuration or components. If you see any other warning, alert, or indicator, be sure to check the product manual to understand the precise meaning. Some chlorine generator models provide notifications that do not indicate the system has stopped or changed operation, for example some models may alert you that the cell is nearing the end of its lifespan, or some models may alert you whether or not the chlorine generator is being controlled by a remote system

If you neither have system warning lights expressly indicating that the chlorine generator has detected an issue, nor any of the other issues above regarding your controller, that indicates that there is either an operational or environmental issue.

System Is Not Being Run At A High Enough Setting Or For Long Enough

It's important to ensure that the salt chlorine generator is set to the appropriate output level and running for a sufficient duration to produce the desired amount of chlorine. This can happen gradually as seasonal temperatures increase, or this can happen suddenly after heavy pool use or inclement weather. If there is a sudden change, you might activate the chlorine generator’s “boost mode” in order to temporarily generate more chlorine to compensate. Otherwise, you’ll want to increase the chlorine output setting that the system runs at daily. Continue to check the resulting chlorine level in the pool and raise the chlorine output level as high as necessary to generate sufficient chlorine. If needed, increase the chlorine generator’s run time to proportionally increase how much more chlorine is generated (ex: 15% more run time would provide 15% more chlorination).

Pool Water Imbalance

Assuming the chlorine generator was initially sized correctly and historically has been able to generate sufficient chlorine, if the system is set to generate its maximum amount of chlorination, this is a clear sign of an imbalance. In other words, an issue is either decreasing the effectiveness of the chlorine and/or greatly increasing the chlorine demand of the water due to having more impurities to sanitize / oxidize. Many people don't realize that when you are measuring free chlorine in the water, you are basically measuring the residual level of chlorine that is not needed to oxidize or kill microorganisms. This means you are detecting the unneeded leftover chlorine (the amount of chlorine added minus that amount of chlorine required to sanitize every bit of the pool water). Measuring low or even no chlorine in the water is not necessarily an indication that your system is not generating chlorine, only that not enough chlorine has been added to the pool. These issues apply to all pools, and not just pools using chlorine generators. Any or even all of the following issues may be at play:

Decreased Chlorine Effectiveness

The slower acting your chlorine, or the more quickly it leaves the pool, the more chlorine must be added to the pool to compensate.

High pH. unstabilized chlorine can become much less effective at killing microorganisms the higher the pH gets, meaning more chlorine must be added to do the job.

Low or high cyanuric acid (CYA). CYA acts as chlorine stabilizer. If it is too low, sunlight can rapidly deplete chlorine, greatly increasing chlorine demand. However, too high of CYA severely weakens the killing strength of chlorine. Modern research shows that there should be no more than a 20:1 ratio of CYA and Free Chlorine; in other words, since your target chlorine level is 1-3 ppm, your CYA should then be 20-60 ppm depending on the chlorine level you are keeping, and no higher. Otherwise you are essentially making your chlorine almost inert, and however hard you chlorine generator is working it might not be enough.

Increased Sanitation Needs (Higher Demand For Chlorine)

Increasing microorganisms, algae using up chlorine. If your chlorine levels aren’t maintained at sufficient levels and/or issues cause reduced chlorine effectiveness, microorganisms can rapidly multiply (along with the scope of your problem). An algae colony can replicate as fast as 3-6 hours in the right conditions! The more things that need to be killed by chlorine in the water, the more chlorine must be added to the water.

Organic waste after heavy pool use or weather. Oils, lotions, sweat, and especially urine (or worse) can cause severe issues, and aren’t going to show up on a water chemistry test. Urine especially causes problems, as it breaks down into urea, ammonia, and nitrates (big problem, see below). Dirt, grass, leaves or other waste that gets tracked or blown into the pool can introduce lots of microorganisms that will begin multiplying; vegetation like grass and leaves will decay in the water which provides lots of nourishment for microorganisms (and can also stain your pool).

Concentrated nourishment for microorganisms.

Phosphates: These are a common source of pool problems because of their prevalence in our environment. As phosphates build up over time in the pool, they provide a “superfood” for algae and other microorganisms, enabling rapid growth. It only takes a tiny bit to significantly raise the pool’s chlorine demand. Phosphate levels should be under 100 parts per billion (ppb), as close to zero as possible. Phosphates can be removed fairly easily by adding phosphate removers to the pool.

Nitrates: They are similar to phosphates in effect (and sometimes in origin) and are equally important to minimize in the pool water, but they are much more difficult to deal with. Nitrate levels should be under 10 parts per million (ppm) and as close to zero as possible. Nitrates, however, can only effectively be removed by the draining of pool water.

Other impurities.

Bromine: There should not be any presence of bromine in the pool, as it can have a detrimental or even hazardous effect. This can occur inadvertently through the use of sodium-bromide based “algaecide” or “chlorine enhancer”.

Fertilizers: Fertilizers make living things grow, microorganisms are living things - keep fertilizer far, far away from the pool! Keep water runoff away from the pool that may contain fertilizer. Fertilizers can cause phosphate and nitrate levels to spike. In areas with agriculture, fertilizers can also easily build up in the pool as wind-blown dust accumulates in the pool.

The presence of any impurities such as copper, iron, other metals or ammonia should be eliminated.

Plan of Action

If any of these pool water issues apply - you need to create a plan of action to address them as soon as possible. It's possible for these imbalances to cause there to be such a high need for chlorination that you will not be able to keep up and maintain a free chlorine residual. Adding extra chlorine or shock may tip the balance and get you by temporarily, but you’re treating a symptom of the problem instead of fixing the root causes. Remember that if the chlorine generator is not displaying errors, it is going to be creating the full and normal amount of chlorine that it is designed to - this is a fixed amount. An imbalance pool can have a higher and higher level of chlorine demand which surpasses the rate of chlorine production. It's not the case that “the system isn’t generating chlorine” because of the imbalance, but rather that the pool isn’t able to achieve a measurable amount of residual chlorine because it is being consumed quicker than it is being replenished.

By identifying the underlying cause of the salt chlorine generator's error lights or warning messages, or the cause(s) for inadequate chlorine residual in the pool, you can take the necessary steps to address and resolve the problem, ensuring optimal pool water sanitization.

If you have a relatively new system and are concerned that perhaps your installation may have been done incorrectly, consider referencing our guide to installing a saltwater pool chlorinator.

4. Signs That Your Salt Chlorinator Might Not Be Working

Calcium flakes in the pool? Pool water looking different? Sometimes life gets busy and you forget to check how things are working, but you catch a glance of the pool as you’re looking outside. It's important to recognize the signs that could be an indication of your salt chlorinator not working optimally. By identifying these signs early on, you can take appropriate action to rectify the issue. Common signs that your salt chlorinator may need attention include:

Low chlorine level

This is one of the most important factors. If your free chlorine level is less than 1-3 ppm (or if your free chlorine level is different than your total chlorine level), this requires your attention. Check your chlorine generator for errors or warnings. If good, you may need to raise your chlorine output level (which can be needed as the season heats up) or temporarily boost it after heavy activity. If you’re having to raise the output more than normal or can’t achieve sufficient free chlorine levels after greatly increasing the system’s output (and run time if needed), you’re likely experiencing a water imbalance that is decreasing chlorine effectiveness, increasing chlorine demand, or both. Review: Pool Water Imbalance troubleshooting.

Cloudy pool water

Cloudiness in the pool water can be an indication of inadequate sanitation caused by a malfunctioning salt chlorinator. It's also possible that there is an issue with the filter, or that flocculent needs to be added to the pool.

Dirty or murky pool water

If your pool water appears dirty or murky despite regular maintenance and filtration, you need to check that the salt chlorinator is operating properly.

Green tint to water or visible algae growth

Algae growth in the pool is going to be the culprit if your pool water is green. If this is happening, or if you see algae spots this can suggest that either the salt chlorinator has not been producing sufficient chlorine to prevent algae growth, or that an impurity or water balance issue is enabling algae growth despite a normal level of chlorination.

Calcium flakes or white mineral scaling visible in cell (high saturation index)

Excessive calcium or mineral scaling visible on is a detriment for the salt cell chlorine generator operation, and can produce calcium flakes in the pool or cause the salt chlorinator to stop generating. If there are frequent issues with calcification, this indicates a high saturation index level, which can be balanced to minimize the amount of scaling that occurs.

Skin & eye irritations

If swimmers experience skin or eye irritations after using the pool, it could indicate inadequate chlorine levels.

High chlorine in the water

Paradoxically, high chlorine levels in the pool water are in issue indicating that the salt chlorinator is not set properly. The system is set to be producing more chlorine than the pool requires. In such cases, it's important to address the issue promptly to avoid potential health risks, as well as to minimize the wear-and-tear on your equipment and maximize its lifespan.

This one should be a given, but maybe you happen to catch out of the corner of your eye that there is a red LED light lit somewhere on your pool equipment pad. If your salt chlorinator has a warning light lit or has an error message on its display screens, check our full salt system troubleshooting guide and consult the manufacturer's manual or website to determine the cause and possible solutions.

Recognizing these signs can help you diagnose a problem with your salt chlorinator and take appropriate measures to resolve it.

If you are troubleshooting your saltwater pool chlorinator and determine you need a new system altogether, check out our guide on choosing the best saltwater pool chlorinator for your pool.

5. Saltwater Pool Chlorinator Troubleshooting Checklist

  1. Verify that the system’s chlorine output is set high enough: If the pool’s chlorine level is low and the system is not running at max output, turn the system up. Ensure that the system is being run long enough. Longer run time provides proportionately more chlorination. A simple rule of thumb for run time is at least one hour for every 10ºF degrees in outdoor temperature.

  2. Verify that there are no system errors: Ensure there are no warning lights or error messages on the control box. If present, check the product manual for next troubleshooting steps.

  3. Check salt levels with a test kit: Test the salt levels in your pool using salt-specific testing strips, chemical kit, digital tester, or store test. Ensure that the salt concentration falls within the recommended range specified by the manufacturer (3500 ppm is a common target level). Adjust salt levels if necessary.

  4. Check and clean your salt cell: Inspect the salt cell for any mineral scaling or debris buildup. Clean the cell according to the manufacturer's instructions using a compatible cell cleaning solution or acid wash. To double verify, clean the cell again in a new cleaning solution - if there is still fizzing, continue to clean the cell. Repeat this until no fizzing occurs when the cell is cleaning with a new cleaning solution. Flush out the cell thoroughly.

  5. Check that all power connections are in place: Ensure that the salt cell is properly plugged into its control box and that the connections are clean and secure. Ensure that the control box is receiving power properly, and that it does not have a blown fuse or tripped internal reset. If your system is plugged into a GFI outlet, check if the test button has tripped. For hardwired systems, check if a circuit breaker is tripped.

  6. Check and balance your pool chemistry: Regularly test and balance your pool chemistry, paying attention to pH levels and cyanuric acid levels. High pH or low cyanuric acid can impact chlorine effectiveness. Maintain a pH level of 7.2-7.6 and a CYA level of 30-50 ppm to reduce strain on the salt cell. Test for phosphates and nitrates: these common impurities cause the pool to require much greater amounts of chlorination and need to be removed.

  7. Ensure proper water flow: A salt chlorinator’s flow switch needs to be triggered properly so the system activates/deactivates when the pump starts/stops. A salt chlorinator’s cell also needs sufficient water flow to ensure it stays 100% filled with water. If there is a flow issue, check your skimmer baskets, pump baskets, and any other “upstream” component for clogs/cracks/leaks, check that your pool water level is high enough, and check that a variable speed pump’s RPMs are not too low.

  8. Visible PCB damage: Ensure there is no damage to the control box. If the Printed Circuit Board (PCB) of the salt chlorinator has any signs of damage, such as burnt components or loose connections, contact the manufacturer.

  9. Ensure that your chlorinator is sized correctly for your pool: Someone else may have installed the chlorine generator on your pool or it may have been improperly sized. Verify that the salt chlorinator's capacity is suitable for the size of your pool. Undersized chlorinators may struggle to generate enough chlorine, while oversized ones can lead to excessive chlorine production.

By systematically following this checklist for troubleshooting your saltwater pool’s chlorinator, you can identify potential problems and take the necessary steps to resolve your issue.

6. Solutions for Common Salt Chlorine Generator Problems

Now, let's explore common problems and solutions for saltwater pools, specifically information on troubleshooting saltwater pool chlorinator issues:

Low Chlorine Level:

  • Check and adjust the salt chlorine generator's output settings higher as needed.

  • Verify that the chlorine generator displays no error lights or messages, and is turning on/off normally with the pump system. Increase pool system runtime if needed.

  • Verify that key water chemistry levels are correct. pH at 7.5, CYA between 30-50 ppm, phosphates close to 0 and under 100 ppb, nitrates close to 0 and under 10ppm. These issues can cause the chlorine to be much less effective or cause much higher amounts of chlorination to be required in order to do the job.

  • If needed temporarily, extra liquid or granular chlorine can be added to the pool to help compensate. This can be done in addition to a chlorine generator running at max output should there be water balance issues, very high pool usage, or unclean conditions which require much more sanitation than normal.

Frequent or heavy calcium build-up / white mineral scaling in cell:

  • Clean the salt cell using a suitable cell cleaning solution or acid wash to remove calcium deposits. This needs to be done as much as necessary in order to ensure the cell stays clean. Heavy build up can require multiple cleanings back-to-back, as the acidity of the cleaning solution can get depleted.

  • This is caused by a high saturation index level, which is contributed to by high calcium levels, high pH, and other issues in the pool water. Lowering the pool’s saturation index under 0.2 will prevent excessive calcification.

Dirty, murky, or cloudy pool water:

  • Confirm that the salt chlorine generator is producing chlorine by checking the output levels are high enough and no warning lights are on.

  • Adjust the output settings if needed to ensure adequate chlorine production, follow “low chlorine level” troubleshooting for other issues that can deplete chlorine.

  • If the pool’s level of chlorine residual is sufficient, there may be issues to address such as a broken pool filter or inadequate water circulation from the pool pump. There may be fine sediment that can only be removed by the pool filter by using a clarifier or flocculant.

Algae Growth:

  • There has been insufficient chlorination. Follow “Low Chlorine Level” troubleshooting. Use the chlorine generator at maximum output and add supplementary chlorine or shock as needed to kill all algae present.

  • Consider the use of algaecide to aid in the treatment to eliminate existing algae and prevent further growth.

  • Brush and vacuum the pool regularly to remove algae spores. All algae must be removed from the pool and the pool filter.

Error codes on the chlorinator's display screen:

  • Refer to the manufacturer's manual or website for the specific error code meanings and troubleshooting steps.

  • Follow the recommended procedures to resolve the error, such as checking for sensor malfunctions or resetting the system.

Skin & eye irritations:

  • There has been insufficient chlorination. Follow “Low Chlorine Level” troubleshooting. Ensure that the salt chlorine generator is producing adequate levels of chlorine to maintain proper water sanitization.

  • Test the water chemistry and adjust the salt chlorine generator settings if needed to achieve optimal chlorine levels.

  • Typical skin and eye irritation in a pool come from “chloramines” which form when there is not enough chlorine to fully oxidize all contaminants. A salt chlorinator eliminates chloramines due to its consistent chlorination as well as the concentrated chlorination and electrolysis occuring in the salt cell. Likely the system is either not being run sufficiently or there are impurities or water balance issues causing rising chlorine demand.

These solutions can help address common salt chlorine generator problems and restore the efficient operation of your system.

7. More Questions About Pool Salt System Problems and Saltwater Pool Chlorinator Troubleshooting Solutions

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