Zodiac LM3 salt light won't go off


New member
Nov 8, 2019
South east Queensland
Does anyone know how to get the salt light to go off on my pool. The chlorinator is 2 years old. I have cleaned the cells (there was nothing on them). I have checked all my chemical levels and they are all correct.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Welcome to TFP.

How did you check your salt level? What is it?

What is your water temperature?

See page 9 in https://www.blpumps.com.au/wp-content/uploads/2017/04/zodiac-lm3.pdf

The light marked CHECK SALT functions automatically when extra salt is needed. Note that the CHECK SALT light may switch on at any salt level between 3000 and 4000 ppm, depending upon the water temperature and mains voltage (see note).This is not a fault but a precaution to ensure that the salt level is never too low.
The salt concentration should normally be around 4000 ppm, but should never be allowed to fall below 3000 ppm, as this can reduce the life of the electrode.

NOTE: Even if the salt concentration is around 4000 ppm, the CHECK SALT light may switch ON if the water temperature or mains supply voltage are too low. In this situation, it may not be possible to set the Chlorine Output to maximum. Addition of more salt to the pool will allow the Chlorine Output to reach maximum settings.