Jandy AquaPure Low Salt Level: Service Code 144

Technical Guide • Updated March 2026

Quick Summary

Code 144 means salinity has dropped below 2.0 gpl (2,000 ppm). The cell automatically shuts off to prevent damage.
The ADD SALT indicator also illuminates on the user interface.
Target salinity is 3.0-3.5 gpl. Operating below 2.0 gpl causes premature cell failure.
Add salt directly to the pool (not through the skimmer), brush to dissolve, and allow 24 hours of circulation before retesting.

What Code 144 Means

The AquaPure's flow/temp/salinity sensor continuously monitors the salt concentration in the pool water. When it detects salinity below 2.0 gpl, the control board generates code 144, lights the ADD SALT indicator, and shuts off the electrolytic cell. This is a protective measure because operating the cell with insufficient salt accelerates electrode plate erosion and shortens cell life significantly.

The cell will not resume chlorine production until salinity rises above 2.0 gpl. During this time, your pool has no automated chlorine production, so you may need to manually dose liquid chlorine to maintain sanitation.

Common Causes of Low Salt

Dilution from rain or heavy splash-out: Every time fresh water enters the pool, salt concentration drops.
Backwashing a DE filter: Water lost during backwash takes salt with it.
Leaks: A persistent leak causes continuous dilution as fresh fill water replaces salty pool water.
Insufficient initial salt: If the pool was not salted to the correct level during startup.
Dirty salinity sensor: Scale on the sensor contacts can cause false low readings. Clean the sensor first if salt tests independently read correct.

How to Add Salt

Turn on the pump to circulate pool water.
Set CHLORINE PRODUCTION to 00% by pressing the down arrow button (A). Do not run the cell while adding salt.
Determine how much salt you need. Use the AquaPure manual's Table 2 or a salt calculator. For a 20,000-gallon pool going from 0 gpl to 3.0 gpl, you need approximately 500 lbs of salt.
Use salt that is at least 99.8% pure NaCl. Evaporated, granulated, food quality, non-iodized. Avoid salt with anti-caking agents (sodium ferrocyanide/YPS). Do not use rock salt or calcium chloride.
Broadcast the salt into the outer perimeter of the pool or the shallow end for quick distribution. Do not add salt through the skimmer, main drain, or surge tank.
Brush the pool bottom to help dissolve the salt.
Allow 24 hours of circulation for complete dissolving and mixing.
After 24 hours, press the SALINITY button (C) to verify the reading is between 3.0 and 3.5 gpl. Press it 2-3 times until the reading stabilizes.
Set the chlorine production rate back to the desired percentage.

Verifying the Salinity Sensor

If the AquaPure reads low salt but an independent test shows correct levels, the salinity sensor may need cleaning.

Remove the flow/temp/salinity sensor from the 3-port cell.
Clean the contacts with a mildly abrasive green fiber pad (Scotch-Brite type) until bright.
Rinse and reinstall.
Turn power off and back on to recalibrate. The unit will display "Wait" during the 6-minute calibration cycle.
Recheck salinity. If the reading now matches your independent test, the sensor was the issue.

Sensor Accuracy Note

Water temperature affects the salinity reading. Always test salinity at the equipment location, not at a remote point. Salt test strips have a large variance (400-800 ppm), so use a Myron L meter calibrated for NaCl or a titration test for accurate results.

How to Prevent Code 144

Test salinity monthly by pressing the SALINITY button. Maintain 3.0-3.5 gpl.
After heavy rain, backwashing, or significant water loss, recheck salinity and add salt as needed.
Fix pool leaks promptly. Continuous water replacement dilutes salt over time.
Clean the salinity sensor annually or whenever readings seem inconsistent with independent testing.
Never add salt without checking the current level first. Over-salting can also damage the system.

Frequently Asked Questions

Will the cell turn back on automatically when salt is added?

Yes. Once the sensor detects salinity above 2.0 gpl after adding salt and circulating for 24 hours, the cell will resume operation at the previously set production rate.

Can I use water softener salt?

Water conditioning salt pellets can be used but take longer to dissolve. Use evaporated granulated salt for fastest results. Never use rock salt due to insoluble impurities.

How much salt does a typical pool need?

A 20,000-gallon pool needs approximately 500 lbs of salt to go from 0 to 3.0 gpl. If you are topping off from 2.0 gpl to 3.0 gpl, you need roughly one-third of that amount.