Pentair IntelliChlor Plus and LT Issues: What Pros and Owners Are Reporting

Quick answer: In October 2025, Pentair issued Technical Service Bulletin A00709 saying new controller firmware (version 1.004) fixes several field-reported issues on IntelliChlor Plus and LT salt systems. Pros and owners report false cell alerts, RESET HMI errors that will not clear, and salt readings that look off. We found no recall, and many units work fine.

What Pentair says was fixed

• INSPECT CELL or CHECK CELL alerts with no visible buildup on the cell blades
• SYS OFF or CHECK CELL alerts with no visible buildup
• RESET HMI not clearing after the reset procedure
• Unresponsive buttons (BUTTON INOP)
• Auto increase problems on standalone units
• WAITING FOR FLOW on automation, with the old address 1 requirement removed

Which units are affected

• LT15, LT25, PLUS30, PLUS40, and PLUS60 cells, power bundles, and IntelliCenter bundles
• Units made on or after October 20, 2025 have firmware 1.004
• The fix is a replacement HMI controller assembly, SKU 523770, which Pentair said would begin shipping November 4, 2025

What pros and owners also report

• Salt readings that differ from independent tests. Community references quote the manual as listing sensor accuracy of roughly plus or minus 500 ppm, so some difference is expected
• Output dropping to 0 percent until the system is reset
• Some owners report early failures within the first months

These are community reports, not Pentair statements. Treat them as signals to check, not proof of a defect rate.

What to do if you have one

• Test salt with an independent method before adding salt or replacing parts
• Do a full power cycle and note any message shown, such as RESET HMI or SPARE
• Record the model, serial number, and manufacture date from the cell
• Ask your distributor or Pentair about bulletin A00709 and an HMI replacement under warranty
• Keep chlorine up with liquid chlorine or tablets while you wait

Warranty notes

• IntelliChlor Plus: 3 years or 10,000 operating hours, whichever comes first. IntelliChlor LT: 2 years or 6,000 hours
• These models are not on the list of Pentair products that skip professional installation, so keep the installer invoice and register the product
• Internet purchases get one year, parts only

Check Pentair for current guidance, since firmware, parts, and policies can change. Use the warranty lookup in the Pool Pros tab to estimate your coverage window.