Check Salt and Inspect Cell Lights on

Two warnings lit at the same time is usually one problem, not two. Check Salt plus Inspect Cell together is the classic signature of a scaled or aging cell, because the panel has no salt sensor and is partly reading the cell when it reports salt. So do not buy salt yet. Test the water with your own kit or meter first, and if salinity comes back in range, the panel is describing the cell rather than the water.

Why the panel lights both at once

A salt chlorine generator does not measure salt. Orenda’s write-up on salinity and cells explains that the cell measures conductivity, not salt, temperature compensated, and converts that reading into a salinity number on the display. Current crossing the plates easily reads as plenty of salt. Current crossing with difficulty reads as low salt.

Scale is a resistor. It sits on the plates, current has a harder time getting through, and the displayed salinity falls while not one grain of salt has left the pool. The same deposit is what makes the unit decide the cell needs looking at. One physical condition, two indicators, which is why they come on together.

That is not just our theory about the plates. Poolside’s troubleshooting guide is direct that a low salt warning is frequently not low salt, and lists scale, cold water, low flow and cell age as causes. Every item on that list moves the number on the panel without moving any salt.

What we can and cannot source here

Being straight about the evidence: Leslie’s troubleshooting guide for these systems covers Check Salt, High Salt, Inspect Cell, No Flow alerts, a flashing Generating light and the HOT and COLD displays as separate conditions. It does not explain what the two together mean, and it publishes no amperage figures. So the reading of the pair as one fault is ours, built from the conductivity mechanism above and the causes Poolside lists. Panels also differ in wording and in what trips a warning, so your own manual is the authority for your unit.

Step one: test the actual salinity

Use a drop test kit or a digital meter and compare the result to the manufacturer’s range, not to the panel. Hayward’s AquaRite manual asks for salt at 2,700 to 3,400 ppm with 3,200 ppm ideal, and Hayward’s Chemistry Quick Start Guide repeats 2,700 to 3,400 ppm with 3,200 ideal.

Two outcomes. If your test says 2,300 ppm, the panel was right and you have a dosing job: the pool salt calculator will size it. If your test says 3,100 ppm while the panel insists on Check Salt, stop reading the display as a salt reading. It is telling you about the path current takes through the cell.

Adding salt at that point is the expensive mistake. The panel will keep complaining, because the resistance is on the plates, and now you are carrying high salinity you have to dilute back out.

Step two: pull the cell and look at it

Shut the system down, remove the cell and look inside it in daylight. Our walkthrough on how to remove a salt cell covers the sequence, including Hayward’s instruction to tighten unions by hand for a watertight seal when it goes back. For what you are looking for, what a dirty salt cell looks like is the comparison page: white crust bridging the plates is scale, and Orenda notes that scale forms on the cathode side of the plates during electrolysis.

If the plates are clean and grey with clear gaps between them, the cell is not scaled, and cleaning it will not fix anything. Move on to temperature and flow below.

Step three: clean it only if it is actually scaled, and go gently

Acid cleaning is not maintenance you do on a schedule. River Pools puts it plainly: cleaning the cell too frequently or using an acid solution that is too concentrated will prematurely erode the coating off the titanium grids. The coating is the part that makes chlorine. Once it is gone, no cleaning brings it back.

Our sources disagree on strength, and the gap is wide enough to matter.

In The Swim’s mix is four times weaker than Hayward’s, since a gallon is 128 fl oz and a cup is 8 fl oz against a quart’s 32. Read the manufacturer’s 4:1 as a ceiling rather than a starting point, and start weaker given the erosion warning. Our full method is on to clean salt cell.

Step four: check the water temperature

Cold water conducts less current, so the panel reads the salinity low in spring and fall with nothing wrong. Hayward’s manual says chlorine generation stops below 50°F, and In The Swim goes further, saying most salt cells won’t work well in water temperatures less than 60 degrees. If your water is in the 50s, both warnings can be honest reports of a cell that physically cannot do the job yet. More on the thresholds at what temperature a salt cell stops working.

Step five: check flow

Low flow is on Poolside’s list of false low-salt causes, and Leslie’s guide treats No Flow as its own alert. A dirty filter, a clogged basket or a failing switch all cut what the cell sees. Hayward’s manual requires a 12 inch straight run of pipe upstream of the flow switch, which is a common install fault worth checking once. Start at flow switch for salt cell.

If the cell really is done

When output stays low with a clean cell, correct balance, correct salt level and warm water, In The Swim’s position is that the cell should be replaced. That is the point where you are choosing between parts, and the numbers matter.

River Pools reports that a well maintained cell will last 3 to 7 years and costs $700 to $1,100 to replace, a control board also lasts 3 to 7 years at $500 to $900, and a whole new generator is only a couple hundred dollars more than a cell alone. That last figure changes the decision. If the cell and the board are the same age and both near the end of that window, buying only the cell can mean paying for labor twice.

Before you spend any of it, work through the five steps above. Our pages on how long does a salt cell last, salt cell replacement and how much a salt cell costs cover the spending side, and salt cell for pool plus the salt cell hub cover how the whole system fits together. The cheapest outcome at this panel is the common one: both lights were describing a cell that needed a rinse.

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