Zodiac lm2-24 problems

ifmx4ever

Member
May 23, 2010
20
Arizona
Hi,

This is my first post to this forum. Amazing information here. Thanks to all. Wish I have found about this site / forum long ago.

Inground pool - pebble sheen - approx 10900 gallons rectangular pool.

I am having issues with my Clearwater Zodiac LM2-24 SWG unit. The output control button to increase the salt production does not seem to work. When this button is pressed, the LED's on the panel should go up. Mine is staying put on the first one and is lit amber in color. However when the super chlorinate button is pressed, all the led's about 5 of them go green and a separate super chlorinate led is also. Green. The Add Salt light - used to be on but it is no longer since I have added salt to bring up the salt level. My reading from the Aquatest Salt test strip shows 4070ppm. The manufacturer recommends 4000ppm.

I just assumed that the cell has gone bad (has been used 4 years) and replaced the cell. However the problem remains. Unable to get the "output chlorine" button to work and light up the LED's.

I also have FC problems (Duh) which I am also trying to fix. FC is about 1-2ppm and TA is about 150ppm. PH is about 7.6 - all using a generic test kit from Leslie's. I am also planning on getting TF100 - testkit very soon. Water is clear but I suspect some algae with brown spots at different locations on the pool.

Any insights to my problem is much appreciated. By the way a call to Zodiac tech support recommended that I replace the cell as they suspected that it is faulty. Now after spending 500bucks I am still stuck with the problem.

ifmx4ever
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
Welcome to TFP!

Some pictures of the brown spots will help us diagnose - sounds like it could be organic or metal staining. Sorry I can't help with the SWG issues...

Where in Arizona are you located?
 

yblaser

Member
Apr 21, 2010
21
Torrance, CA
Hi ifmx4ever. I have an lm2 unit as well with the exact same symptoms. It does however work intermittently. We had the cell replaced under our home warranty and as with you it did not fix the problem. I took the unit apart and noticed that water had been leaking through a crack in the top of the unit causing corrosion on the contol board electronics. I have a new board in hand and plan on replacing tomorrow. I expect this to fix the problem but will let you know how it goes.

-Peter
 

malcolmb5325

In The Industry
Sep 5, 2009
166
Sydney, Australia
the lm's have only 2 pcb's, a control pcb which is located under to top label and the power pcb which is located on the aluminum back plate which controls all the internal power and the power to the cell. I would suspect the power pcb has gone as you have already replaced the cell and it is still faulty.
 

rneiraaz

New member
Jul 11, 2011
1
Did anyone ever find the solution to this? I have the exact same problem - amber chlorine output led, cant adjust output level unless i use the 'superchlorinate' setting (which I've been told damages the cell if used too often). I just replaced the salt cell and it had been working fine, so i dont think its the cell. Any help would be GREATLY appreciated. Thanks!


-Ryan
 

getbit

LifeTime Supporter
Jul 7, 2011
6
I'm having the same problem with the LM2-40 unit and didn't want to spend hundreds of dollars chasing it down.
I was considering a new cell as well, but since it works in super chlorinate mode, I reasoned that it is still functioning (enough) and shouldn't be the culprit.
Malcomb5325 suggested the power pcb (a year ago) and now suggests the control pcb...well, which should it really be?
If you changed both boards and the cell, you could have just purchased a newer system with a warranty.
Frustrating stuff...
 

getbit

LifeTime Supporter
Jul 7, 2011
6
Update...I replaced the control board and everything is working again.
When the cell finally bites it, I think I'm going to consider replacing the system.
 

cavanrw

Member
Jun 1, 2016
5
London
What do I do if my Salt Chlorinator LM2 is not retaining the output power settings each morning when the timer starts the pool back up? Do I need to change the rechargeable backup battery in the system? The manual does not seem to have any contingences for this type of problem. Any ideas?
 

bb_sam

New member
Jul 19, 2016
1
Toronto, Canada
Hi,

This is my first post to this forum. Amazing information here. Thanks to all. Wish I have found about this site / forum long ago.

Inground pool - pebble sheen - approx 10900 gallons rectangular pool.

I am having issues with my Clearwater Zodiac LM2-24 SWG unit. The output control button to increase the salt production does not seem to work. When this button is pressed, the LED's on the panel should go up. Mine is staying put on the first one and is lit amber in color. However when the super chlorinate button is pressed, all the led's about 5 of them go green and a separate super chlorinate led is also. Green. The Add Salt light - used to be on but it is no longer since I have added salt to bring up the salt level. My reading from the Aquatest Salt test strip shows 4070ppm. The manufacturer recommends 4000ppm.

I just assumed that the cell has gone bad (has been used 4 years) and replaced the cell. However the problem remains. Unable to get the "output chlorine" button to work and light up the LED's.

I also have FC problems (Duh) which I am also trying to fix. FC is about 1-2ppm and TA is about 150ppm. PH is about 7.6 - all using a generic test kit from Leslie's. I am also planning on getting TF100 - testkit very soon. Water is clear but I suspect some algae with brown spots at different locations on the pool.

Any insights to my problem is much appreciated. By the way a call to Zodiac tech support recommended that I replace the cell as they suspected that it is faulty. Now after spending 500bucks I am still stuck with the problem.

ifmx4ever

I had this exact problem and I thought I would share my fix -- there seems to be a lot of conflicting information about how to fix this issue (ie as between a new salt cell, a new PCB board and a powerboard).

I have the Zodiac LM2-24. I noticed that my pool had very low/zero chlorine levels. The Zodiac display showed an amber light at the far left (ie calling for low/no chlorine), the system also appeared to be automatically resetting itself. It would shut itself off, restart and still show that amber light. I was able to push the super chlorinate button which would light up in green and then allow the main chlorine output lights to turn green. But, the system continued to cycle itself off then turn itself on. It would do this in 10-15 second intervals. I figured I had a problem with the PCB Board (based on the comments above). But, I also knew that my salt cell was 6-8 years old so it was equally likely (and more probable) that the salt cell was dead.

I bought a new salt cell. Installed it, and I was experiencing the exact same symptoms -- just like others reported in this forum. I waited 12 hours thinking that the system could somehow reset itself -- I tried to turn the power off at the circuit breaker ... no luck. I had almost resigned myself to buying the PCB board. I then decided (after shutting off the power) to open the Zodiac control panel and simply disconnect the ribbon connecting the PCB board to the main board -- in the hope it would reset the system. Sure enough, after plugging the ribbon connector back in and turning on the power, I noticed that the amber light was still on but now it was flashing. In reading the LM2 manual, it appears that that is the system cycling through negative polarity. You can fast track that test by pushing the hidden "service" button (holding it for 5 seconds) -- and the flashing light shut off. The display went blank, then it powered up again and this time the green lights for chlorine output were light up. I was able to scroll through the green output and/or push super chlorinate without any issues.

Issue resolved. It was the cell after all.

Bottom line, if you replace the cell and find that the display isn't working, don't assume that the PCB needs to be replaced. I learned from reading the manual that there is a backup battery in the main Zodiac panel such that even by turning off the power you're not really cutting power to the PCB to reset it. You should disconnect it from the main panel and then replug it back in to force the reset.

My 2cents....
 

Bill Newlands

New member
Nov 24, 2016
1
Warana Australia
The polarity can also be the reason why the chlorinator lights don't go up and down, you can just swap the out put wires around or there could be a hidden switch like on my LM 24 ,I found it located approx 1 1/2 inches below the super chlorinat button, I had to hold it in for a few seconds then the polarity changed itself, hope this helps someone.
My wife accidently pressed it, and the add salt light came on, but it's now fine
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,721
Sydney, NSW, Australia
Great help here and possible fixes for the problem.

Anytime you see 0-1 FC, bring your FC up to target with bleach / chlorinating liquid immediately. Even if you get it fixed right away, it takes time for the cell to bring the FC up to a safe range. Glad to learn these options for people in this situation. Thanks!!
 

cavitron

New member
Aug 18, 2017
1
Canada
Before you consider replacing the boards, I recommend trying the cell as that fixed the problem in my situation. Symptom was "Add-salt" and amber light on at the same time intermittently. Pressing the "hidden" Service/Polarity button would temporarily solve the problem. I actually unnecessarily tried replacing both boards before attempting the cell primarily because I saw this thread. The cell was old and I should have known better. Luckily I got a refund for the boards. Advice is if you get the double yellow light in specific polarity only and the cell is old, replacing the cell first.
 

Flyguy208

New member
May 27, 2020
1
Canada
Just had the same issue as the OP with my LM2-24. I just opened my pool, and everything on the control panel appeared normal. I added my first batch of salt and a few hours later, amber light with no ability to change output level. I turned the power to the salt cell on and off and did a reset of the system using the “hidden” reset button below the Superchlorinate button. Issue appears to be resolved, as the output level returned to where it had been set (lowest green level) and I could once again control output level from the control panel