Troubleshooting Cell Life Low / Remaining Messages

Some Saltwater Chlorine Generators (SCGs) provide messages relating to the (remaining) cell life that can take the form of “Cell Life Low,” “Low Efficiency Cell,” or variations on those. Others may not provide explicit messaging, but will have provisions to display the salt cell’s cumulative, operating hours. And of course, a large number of models provide no tracking of cell use or condition.

What actually takes place as your salt cell wears out and fails? As you may know, the chlorine production needs electric current passing through temperate saltwater between the ruthenium coated blades (or plates) of the salt cell. As the cell wears out, the coating on the cell degrades, the voltage increases to push the current, and eventually the required voltage reaches the equipment’s limit and can no longer maintain current to the blades.

However, with salt chlorinators which give messages about cell life, most models use operating hours as one of the primary factors when the system alerts you about remaining cell life. This means that depending on the model, you may not need to immediately replace the cell.

What They Aren’t

• Cell Life tracking and warnings do not measure the chlorine output of your SCG.
• Similarly, there is no measurement made of the coating thickness or the remaining ruthenium layer.

What They Are

Indications of cell life and remaining cell life are strictly inferences made from indirect measures of the cell’s usage and condition.

• Tracking Operating Hours: The most straightforward approach is tracking the number of hours the SCG is operating, or to be more precise, the number of hours the cell has been energized with current flowing to the plates and chlorine produced. On the surface, this is a compelling number with salt cells commonly rated for their expected lifespan in hours. The runtime on cells is helpful for keeping track of usage, but can really only give you a sense of where the cell may be with regard to its remaining life. An expected lifespan of 10,000 hours doesn’t mean that every cell reaches that number and, similarly, that not every cell goes no longer than 10,000 hours.
• Tracking Operating Patterns: The least common method is one which tracks operating hours and observes the operating patterns, whether the voltage is perhaps increasing and/or the amperage (current) dropping. Tracking both the operating time along with measuring the cell efficiency—maintaining current without the voltage increasing—allows for better predictive behavior, but still remains only an estimate of cell condition.

How Do We Know (If) The Cell Life Is Over?

Warnings of this type are typically estimates—Prepare, don’t panic. Depending on your system and how the warning is determined, the caution may be on target or premature. Put simply, if chlorine is still being generated, continue to use the system as long as possible to get the most value out of it.

For many classic models, the most common symptoms of a cell that is at the end of its useful life* are a Check/Clean Cell message that will not go away in spite of cleaning along with a false Low Salt warning.

To be sure you need to replace your cell, address all of these issues first. If you have confirmed all of these items AND have an error on the salt chlorine generator which is not allowing it to generate chlorine, you can generally be confident that cell replacement is required:

• Have you followed all troubleshooting for the specific error displayed? (If no error is displayed, cell replacement is likely not called for)
• Have you verified with test strips / titration drops / digital tester that your pool water’s salinity is in the proper range?
• Have you thoroughly cleaned the cell multiple times, so that when cleaning it with freshly-mixed solution no fizzing occurs within the cell?
• Have you ensured that water is 100% filling the cell while it is operating with no air pockets or large bubbles?
• Have you confirmed that the controller is set to the correct cell type (if applicable)?
• Have you confirmed that all cell cable connections are clean, tight, and free of damage?
• Have you confirmed that water temperature is within proper operating range?
• Have you confirmed that the error comes on within the first few moments of turning the system on, and comes back on just as quickly if the system’s power is turned off / on?
• Has the cell been used for years (as long as previous cells of the same model have lasted)?

*What we think of as a salt cell’s “useful life” can be extended indefinitely if kept on hand and used as a winter/bypass cell which can be used to maintain circulation in place of the newer, functional cell when a freeze risk exists or if the newer cell is being cleaned or serviced. While this isn’t the same usefulness as generating chlorine, consider keeping an old cell for these purposes.