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If your Pentair IntelliChlor IC40 salt cell has died, you need a replacement that fits the same plumbing and will still run for years. The main risks are buying the wrong model number and getting a unit that fails early.
Our No. 1 pick is the Pentair 523735 IntelliChlor Plus40 replacement cell, the genuine OEM part rated for pools up to 40,000 gallons. Two other cells cover a lower price and a cheaper third-party option.
1 Pentair 523735 IntelliChlor Plus40 | 2 Pentair 523735 IntelliChlor Plus40 | 3 Aqualix IC40 Salt Cell | |
|---|---|---|---|
| Best for | Best overall | Best value OEM | Best budget |
| Pool capacity | Up to 40,000 gallons | Up to 40,000 gallons | Up to 40,000 gallons |
| Fit | Drop-in for IC40 (EC-520555) | Direct replacement for IntelliChlor IC40 (520555) | Fits Pentair IntelliChlor Power Center system |
| Requires | IntelliChlor Power Center (sold separately) | IntelliChlor Power Center | Not listed |
| See priceat Amazon | See priceat Amazon | See priceat Amazon |
Pentair 523735 IntelliChlor Plus40Best overallMost recommended by reviewers
See priceat Amazon
Pentair 523735 IntelliChlor Plus40Best value OEM
Aqualix IC40 Salt CellBest budget
The most direct OEM-style upgrade for a 40,000 gallon pool.
Most recommended by reviewers
Check price at AmazonPrices and availability on Amazon change often.
For someone replacing an IC40 and wanting the most straightforward path, the Pentair 523735 IntelliChlor Plus40 Replacement Cell is our pick, since it is a drop-in fit for the IC40 with the same plumbing and is rated for pools up to 40,000 gallons.
The cell is listed as a direct replacement for the EC-520555 IC40, so you can swap it in without adding plumbing. Its chlorine output is rated at 1.40 lbs every 24 hours at 100%, and it is designed for pools up to 40,000 gallons. The redesigned conductivity sensor is meant to give more accurate salt readings. Owners on r/Pools say the IC40 is a solid unit and that failures under warranty are uncommon, though reports of early failures on newer firmware also circulate.
The cell needs the IntelliChlor Power Center, which is sold separately, so budget for that if you do not already own one. Some owners warn that recently updated units may not be a direct one-to-one switch, so confirm your model and firmware before ordering.
If it's not for you, the Pentair 523735 IC40 Plus Replacement is the OEM alternative at a slightly lower listed price with fewer specs, and the Aqualix IC40 Salt Cell Replacement suits buyers who want a much lower price and accept that it is not a Pentair part.
This is the cell most owners of an IC40 will need, since it is designed as the successor part for the same system. Its stated output of 1.40 lbs of chlorine per 24 hours at 100% covers pools up to 40,000 gallons, and the redesigned conductivity sensor is meant to give more accurate salt readings.
The main caution comes from community discussions: some buyers reported failures on earlier firmware and advised checking the firmware on a new unit. Buy from a reputable seller, confirm the model number on arrival, and keep your receipt.
The same OEM-style Plus40 cell at a slightly lower listed price.
Prices and availability on Amazon change often.
This listing is for the same OEM Plus40 cell, so if the top pick is out of stock or priced higher, this is the closest alternative. It is described as a direct IC40 replacement and a genuine OEM part for PLUS40 systems.
The listing gives fewer details than the top pick, so check the model number carefully before ordering, since one expert review reviews show that substitutes can ship in place of the model you ordered.
A third-party cell at a lower price, for owners who accept a non-OEM part.
Prices and availability on Amazon change often.
For owners who want to spend less, this third-party cell fits the Power Center system and is priced well below the OEM options. Community discussions note that some third-party cells have lasted better than OEM units for certain owners, though results vary.
Because the chlorine output figure is not stated in the listing, check that it suits your pool volume before buying, and confirm the warranty terms with the seller.
Reader reports vary. Some owners say a unit lasted about seven years, while others report failures within a year, so inspect and clean the cell regularly.
Installation adds to the cost if you hire a pool professional.
Reader discussions say the IC40 is end of life and that Pentair now ships the Plus40 as its successor, so check the model number before ordering.
Signs include low chlorine output, false low-salt or no-flow alerts, and visible calcium buildup on the plates. Inspect the cell at least every three months.
Remove scale from the plates using the recommended cleaning steps, and keep salt levels near 3,600 ppm. Calcium buildup reduces chlorine production.
Turn off power, unscrew the unions at each end, swap the cell, and reconnect. Take a photo of the old cell first to match flow direction, and hand-tighten the unions.
Why trust BullseyeBuy
This shortlist is built from three Amazon listings that are in stock now, checked against the model number, the stated pool capacity and the reader discussions about failures and substitutes. Recommendations focus on fit, firmware and the warranty route.
Our expert team tests products when it is needed and researches online and in interviews. Every guide is fact-checked and edited by a real person.
The BullseyeBuy editorial team · Updated Nov 6, 2026
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