Salt Gen not producing Cl

I have a Zodiac Clearwater Salt Chlorine Generator model C170 which is not generating any chlorine whatever. Everything looks like it is working correctly in that I have a salt content of 4300ppm and the meter reading goes to 98%, but the yellow light is often on indicating a low salt condition or cell is in need of cleaning. In my case it is neither. The cell was replaced last August and was turned off sometime in October. I just started it up again in Feb when I noticed it was not producing chlorine. I checked out the water hardness and found out it was over 12000 ppm. I changed the water 100% and the hardness is now down to 250 ppm. I put in 10 x 40# bags in this 12000 gallon pool, but it will not produce Cl. When the salt gen is running, the voltage at the plugin teminals is 6.7 and there are bubbles visible through the plastic casing. The temperature of the water is only 65. With the new water I have put in 4# cyanuric acid, which is probably not enough but I want to leave it 10 days or so to get an accurate reading. A pool store told me that unless I have a CYA reading over 85 my generator will not be able to produce any chlorine. I always thought that the amount of cya prevented the Cl from dissipating quickly, not that low cya in itself prevented cl production? Have I got a bad cell or circuit board, and how can I tell? In theory I could replace my cell with one that is known to work, but in the real world how could I find one for such a test?

"A pool store told me that unless I have a CYA reading over 85 my generator will not be able to produce any chlorine." -- totally bogus.


"I checked out the water hardness and found out it was over 12000 ppm" -- also bogus- was that a typo?

Reading through your post, it's not clear that you've cleaned the cell since you had high calcium (not: 12,000 ppm, but presumably still too high). If you haven't, I would recommend cleaning the cell, per the manual, just to rule that out as an issue.

PoolDoc

Correction - hardness was 1200 ppm! (Sorry my typo)
Yes, the cell is spotless.

I didn't believe that with low cna no chlorine is produced, but thought I would check just to be sure

I have come to the conclusion that it will be cheaper and far less time consuming to go back to chlorine tabs in a floater. I should also save on acid as when the SWG was working I was using a lot of acid. I think this was caused by the generation process itself rather than just having salt in the pool, but I guess I will be finding out for sure!

The greater need for acid when using an SWG is from the increased aeration by the hydrogen gas bubbles and from some undissolved chlorine gas outgassing (especially if the pipe run from the SWG to the pool is short). You can reduce the effect of the aeration by lowering the TA level -- usually to 70 ppm if not lower -- and by targeting a somewhat higher pH range, usually 7.5 to 7.8.

Just out of curiosity...have you tried acid washing the cell even though it looks clean?

Is the cell actually not producing or is there just no chlorine residual in the water? (try losing the cell union after the cell right after shutting it off to collect a water sample and test for chlorine. If there is chlorine then the cell is working but not keeping up with the chlorine demand in the pool.

4 lbs of cya will raise your 12k gallon 40 ppm so it will only get your half way there assuming CYA is at 0 ppm.

I would suggest acid washing the cell and then testing a water sample from the union to see if it's working. If it is then you have a chlorine demand issue going on. If so I would test the pool for ammonia, particularly if you had normal CYA when you closed the pool and it's now very low or gone.

Also, the cell will not generate in cold water! I am not suprised it was not working in Feb. You need to wait for the temp to rise a bit to really know if it's working or not. Once your water reaches about 70 deg. you will have a better idea what is going on.

A new development is leaving me even further confused. As I have previously stated everything regarding the SWG is working in theory, i.e., meter at 100%, bubbles being produced, slat over 4000ppm, but zero chlorine. Today I filled a bucket from the pool and placed the cell into it and connected the terminals and turned it on. I let it run for a minute or two and the water turned cloudy. I then drop tested the water in the bucket and the sample turned beyond yellow to orange, ie., chlorine production of the scale! I reinstalled the cell unit to its inline plastic casing and again took poolwater samples at each of the entry points into the pool and sure enough zero chlorine! If the SWG was pumping water through an underground leak my water level would have gone down as I have had the autofill turned off for a week or so. I had previously loosened the endcap and sampled the water leaking which showed no signs of Cl. I was unable to test it at the other end of the plastic housing as the cap was either molded or cemented on. However if somehow there was a blockage in the lines and the water was circulated by passing the pool then surely I would have found some trace of chlorine when I tested it at the leaking endcap? This is driving me crazy as there does not seem any logic to it. I really would appreciate any ideas as to what may be going on.

Kinda sounds like you have some organics in your water which are consuming your chlorine. I would suggest pouring in a couple of 96oz jugs of plain, unscented, 6% Clorox bleach in front of a return while the pump is running, and check the FC level after 30 or 40 minutes That should raise you 12000 gallon pool to at least 7ppm. If it does not you have an infestation that you will need to deal with.

I agree with Ohm_boy