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How to Check a Pool Chlorinator Cell With a Multimeter

To check a pool chlorinator cell with a multimeter, you measure DC voltage at the cell with the chlorinator powered and producing, then compare the reading with the range in your controller’s manual. The Hayward Aqua Rite diagnostics manual lists a cell voltage range of 22.0 to 26.0 VDC for its Turbo Cell, and it asks that cell voltage and amperage be checked in both polarities. A multimeter can confirm whether the cell is receiving direct-current voltage at all, but it cannot tell you the cell’s chlorine output by itself. Always switch off power before you disconnect or reconnect anything.

Quick answer

• Set the meter to DC volts, not AC volts. Salt chlorinator cells run on direct current.
• Compare your reading with the cell voltage range in your own controller’s manual. The Hayward manual gives 22.0 to 26.0 VDC for the Aqua Rite Turbo Cell.
• Check both polarities. Hayward’s manual says to switch polarity through the main switch cycle, so a reading in one direction alone does not complete the check.
• If the reading is out of range, or there is no reading at all, stop. Check the breaker, the time clock and the jumper settings first, then call a qualified technician for anything inside the control box.

Why a chlorinator cell is a DC load

Most salt chlorinators use a control box that takes household alternating current and converts it to low-voltage direct current for the cell. The cell has plates that carry that DC current through salty pool water. The electrolysis at those plates produces chlorine. This is the reason a standard AC voltage check does not tell you much about the cell itself. An AC meter setting will read the household supply at the control box, and it may read close to zero or a random value at the cell leads.

Because the cell is a DC load, a meter set to DC volts is the right starting point. The Fluke guide on DC voltage explains the basic procedure: select the DC voltage function, insert the black lead into the COM jack and the red lead into the voltage jack, and place the leads on the test points. The same guide notes that when the leads are reversed, the meter shows a negative sign. That sign is useful when you are comparing both polarities of a cell.

What the Hayward manual says about cell voltage and amperage

The Hayward diagnostics manual for the Aqua Rite and Aqua Rite XL includes a section titled “Check Salt & Inspect Cell LED flashing or ON.” In that section, the manual says to check cell voltage and amperage in both polarities. It gives a voltage range of 22.0 to 26.0 VDC. It also gives amperage ranges that depend on the cell size:

Turbo Cell size (per the manual)	Amperage range (per the manual)
T-15	3.1 to 8.0 amps
T-9	2.3 to 6.7 amps
T-5	1.9 to 5.7 amps
T-3	1.3 to 4.5 amps

Two details in the manual matter for a homeowner. First, the cell size setting in the controller must match the installed cell. The manual says that if the wrong cell type is selected, the salt level, amperage and voltage readings will not be correct, and the system will turn the chlorinator off. Second, the Check Salt and Inspect Cell LEDs can also come on when the wrong Turbo Cell type is set or when the cell is unplugged. An LED warning is therefore not, by itself, proof that the cell has failed.

The excerpt we opened does not state the exact probe points for the voltage and amperage checks in the Step C procedure. Read your own model’s manual before you place the meter leads, so that you measure the same points the manufacturer uses. Where the manual does not name the points, this guide does not name them either.

What you need before you start

• A digital multimeter with a DC voltage setting. Confirm the meter’s maximum DC range is above 26 VDC before you start. Many meters choose the range automatically.
• Insulated test leads in good condition. Replace leads with cracked insulation before you test.
• The manual for your exact chlorinator and cell model, with the cell size written down.
• A notebook or phone note to record readings from each polarity.
• A way to confirm the pool’s salt level, if your controller reports it. A low salt level changes the cell output, so a low reading may reflect the water rather than the cell.

Safety before you touch the cell

A pool chlorinator is an electrical appliance connected to mains power, and the control box can carry dangerous voltage even when the cell itself runs at low DC. The Hayward manual warns that hazardous voltage can cause shock, burns, serious injury or death, and it says that only qualified technicians should remove the control panel. A homeowner should not open the control box.

Follow these rules before any test:

• Turn off the chlorinator at its breaker. Do not rely on the controller’s own off switch.
• Keep the cell wiring dry where you connect the meter. Water and metal meter tips do not mix well with mains equipment.
• Never reach into the control box, and never test inside the box unless you are a qualified technician.
• If the cell has been running, allow it to sit before you handle it. The manual’s cleaning section describes handling the cell as a maintenance task, and this guide does not add any separate heat-safety figure.

Step-by-step: checking cell voltage with a meter

The steps below follow the logic of the manufacturer’s check, combined with the general DC voltage method from Fluke. They assume the controller is powered and the system is producing chlorine, because the Hayward check is designed for that state.

1. Confirm the cell type. On the controller, check that the cell size setting matches the cell label. A mismatch makes the readings meaningless.
2. Set the meter to DC volts. Use the highest DC range if the meter is not auto-ranging. Place the black lead in COM and the red lead in the voltage input.
3. Find the test points named in your manual. Do not guess. If your manual names the cell terminals, measure there. Do not probe the wire nuts inside the control box.
4. Read the voltage with the cell running. Note the number, then compare it with the range for your model. For the Hayward Aqua Rite Turbo Cell, the manual gives 22.0 to 26.0 VDC.
5. Reverse the polarity. Swap the leads, or follow the manual’s polarity step, and read the voltage again. The manual asks for both polarities, so write both numbers down.
6. Compare the readings. If both are in range and the controller shows no alarm, the cell is likely receiving voltage. If one or both are out of range, move on to the checks below.

When the reading is out of range or there is no reading

The Hayward manual’s troubleshooting logic gives a useful order. It does not ask a homeowner to open the panel, but it shows what a technician checks.

• No voltage at all. The manual’s no-voltage branch first asks whether the breaker or time clock is off. It then checks the input jumpers. For 115 to 125 VAC supply, the manual shows jumpers on pins 1 and 2 and on pins 3 and 4. For 220 to 240 VAC, the factory default is jumpers on pins 2 and 3.
• Fuse. The manual’s branch for no LEDs or no display includes a continuity check of a 20-amp slow-blow fuse. A blown fuse is replaced, not bypassed.
• Transformer. The manual gives a resistance range of 2.0 to 2.9 ohms for the primary-side readings it lists. If a reading falls outside it, the manual says the transformer is faulty. This is a technician test inside the control box.
• Low DC on the board. The manual gives 18 to 33 VDC between the black and red wires on the main board, and it says that low or no voltage calls for replacing the rectifiers. Again, this is for a qualified technician.

A homeowner’s useful role is the first set of checks: the breaker, the time clock, the controller setting and the jumpers if you can see them without opening the panel. Anything that requires removing the panel belongs to a technician.

How to use a resistance check

A resistance check is a different test from a voltage check. Fluke’s guide on measuring resistance explains that a digital multimeter in resistance mode measures how hard it is for current to flow through a component. Fluke also notes that loads such as motors and solenoids change resistance over time. A resistance reading on a cell, with the power off and the leads disconnected, can show whether a connection is open or shorted, but it does not replace a voltage and amperage check made while the system is running.

Use resistance for the cable and the connectors only with the power off. Fluke’s guide notes that a meter in resistance mode can show OL or an open reading when the leads are not connected to anything, so a high reading alone is not proof of a fault. Connect the leads to the component, wait for the reading to settle, and compare it with the expected value from your manual.

What the readings tell you

A cell voltage inside the manual’s range, with the chlorinator producing and no alarm, suggests the power path to the cell is working. A reading that is low in both polarities can point to a supply problem, a control problem, a worn cell, or a salt level that is too low for the system to run the cell at full output. The meter cannot separate these causes on its own.

A reading that is good in one polarity and bad in the other is a different pattern. The Hayward manual asks for both polarities for a reason, and a one-sided result should send you back to the manual rather than to a guess about the cell.

A reading of zero volts on the cell terminals while the controller shows a salt or inspect-cell alarm is worth a technician call. The manual lists these alarms as signs that the system should be checked, not as a homeowner repair.

Common mistakes

• Using AC volts. A cell is a DC load. An AC setting will not give a meaningful cell reading.
• Checking the wrong cell type. The manual says a wrong cell type setting makes the readings wrong and can switch the chlorinator off.
• Reading one polarity only. The manual asks for both.
• Testing with the power on inside the control box. Panel removal is reserved for technicians, as the warning above explains.
• Trusting a single number. A low salt level, a dirty cell or a wrong controller setting can all change the reading.

When to call a technician

Call a qualified technician if the cell voltage is out of range in both polarities after you have checked the breaker, the time clock, the cell type and the salt level. Call sooner if you see scorching, a burning smell, damaged wiring or water near the control box. Do not open the control box yourself. The manual’s warning about high voltage and the requirement for qualified technicians both apply to a homeowner who is simply curious about the readings.

How we chose

This guide covers one question: how a homeowner can use a multimeter on a salt chlorinator cell, and where the readings fit in a manufacturer’s check. We opened the Hayward diagnostics manual and two Fluke method pages on 2026-10-28 and used only what those pages state. We did not compare brands or rank products, and no product is recommended here.

What we could not verify

• The exact probe points for the voltage check in the Hayward Step C procedure. The excerpt does not name them, so this guide does not either.
• Chlorine output in parts per million for any cell reading. The sources do not provide a meter-to-output conversion.
• Cell voltage or amperage for other manufacturers. The Hayward figures apply to the Hayward manual we opened, and other brands use different specifications.
• Any figure for a cell running under a different salt level or temperature than the manual describes.

FAQ

Should I use a multimeter on a salt chlorinator cell?

Yes, for a DC voltage check of the cell as described in the manual, and for resistance checks on wiring with the power off. A meter does not measure chlorine output directly. Read the manual first and follow its points.

What voltage should a chlorinator cell read?

The Hayward figure in this guide is the 22.0 to 26.0 VDC range from the Aqua Rite manual. Other brands and models use different figures, so check your own manual rather than this one.

Why does my cell read zero?

The most common reasons in the manual’s order are an off breaker, a time clock that is off, a wrong cell type, a missing input jumper, or a cell that is unplugged. Check those before you conclude the cell has failed.

Does polarity matter for the reading?

Yes. The Hayward manual asks for both polarities. Note the sign of each reading and compare the two numbers.

Can I test the cell with the pool water wet?

Keep the meter connections dry and secure. Do not let water reach the control box or the connectors. The safe approach is to use the manufacturer’s test points and to stop if anything looks damaged.

When is it safe to open the control box?

The manual says only qualified technicians should remove the panel. Do not open it yourself.

Bottom line

Use a DC voltage setting, check both polarities, and compare the reading with the cell voltage range in your own manual. For the Hayward Aqua Rite Turbo Cell that range is 22.0 to 26.0 VDC. Check the breaker, the time clock and the cell type before anything else, and leave the control box to a qualified technician.

Related guides

For a general introduction to the meter, read how to use a multimeter step by step before you start. For a different low-voltage check on a home system, see the guide to voltage testers for home use, which covers the limits of a basic tester.

Sources

• Hayward Industries, “Aqua Rite & Aqua Rite XL Diagnostics Manual,” Software Revision 1.50, copyright 2009. Copy opened at https://images.inyopools.com/cloud/documents/aquarite-troubleshooting-guide.pdf on 2026-10-28. Copy is hosted by a retailer; the document is labelled as Hayward’s.
• Fluke, “How to Measure DC Voltage with a Digital Multimeter.” https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter, opened 2026-10-28.
• Fluke, “How to Measure Resistance with a Digital Multimeter.” https://www.fluke.com/en-my/learn/best-practices/test-tools-basics/digital-multimeters/how-to-measure-resistance, opened 2026-10-28.