My Aqua Plus salt water chlorine generator with a T-15 cell has stopped producing chlorine. It is under warranty, and I have asked both the pool builder and Hayward to repair it ASAP. However I would like to open a discussion as to what is the problem.
Around the beginning of the month, the system started to give me low salt errors. Previous to that, it was giving salt readings of 3000 to 2900 ppm. I would clear the error and it would start working again, only to trip out hours later. I opened a tech support case with Hayward on the erronious salt readings. They sent me a "recalibration" procedure which consisted of updating the time average salt value with the instantous one. Of course this did not work.
On 12/08/2007 I had the water analized by a pool store, and the salt level was 2800 ppm. I also purchased some salt test strips, and they gave the same reading. The range for my generator is 2700 to 3400 ppm. I then added 20 lbs of salt, which cured the low salt errors on the generator.
The next Monday I tested the water and had 0 free chlorine. I added one quart of 10% bleach, and waited one hour. The free chlorine level still tested zero. I the decided to shock the pool. According the the Pool Calculator I added an additional gallon of 10% bleach. This raised the FC level to above 10 ppm. This level took a long time to come down, by 12/15/2007 it was about 3 ppm.
The level continued to drop, so I raised the output on the generator. For the previous month a setting of 7% was giving me a FC level of between 3 and 4 ppm. I continued to raise it finally reaching a level of 25%! By this time the FC level was down to .25. The evening of the 20th I ran the SWCG in superchlorinate mode for one hour. This raised the FC level to .94. Again after that the levels still kept dropping. On the 22nd I said enough, and shut down the SWCG and started to add bleach. The readings after adding 32 oz 10% bleach:
While the SWCG was working I took the following readings from the diagnostics: +26.59V, +5.99A, 73F, 3000ppm. I removed the chlorine cell and inspected it. The plates were shiny and clean. All I saw was several small pieces of plastic (probably burs from the pipe). So my questions is what can prevent a chlrine cell from producing chlorine?