So I have a long saga this season of not having a reliable pool heater. It works intermittently since start up in early June. Warranty repair person has been here twice and twice said all is well without really doing anything. That long sad story can be found here:
My question here is to see if my chemistry could have caused a problem. They are coming out tomorrow to clean out the heat exchanger. They have not talked to me about why they think that is the issue but did email me that is what they are doing tomorrow. I want your input to see if I could have messed up the chemistry so bad as to ruin the heat exchanger after only one season of use, plus about a month this season -- that would be about 90 days total. I drain and re-fill each season, so I start with completely new water each season. Here are current numbers. Keep in mind I have only been full for a month, so although I am trying to get my TA down, it takes time. I add muriatic acid every time I get to 7.8 and go down to 7.2. Sometimes I even add at 7.5 to go down. My pH has never been below 7.2 or above 7.8. I test at least once per day and often in both the morning and evening.
CYA: 20 or slightly higher
Salt: about 700
Pentair's manual says if I don't stay in their parameters I will void the warranty. No one has suggested that is a problem in my repair story thus far, but my understanding is if they say the heat exchanger needs to be cleaned they are likely to blame the water chemistry.
Per Pentair the parameter are:
No mention of CYA in manual
FC: 1-5 (ideal 2-4)
CC: 0-.2 (ideal 0)
pH: 7.2 - 7.8 (ideal 7.4-7.6)
TA: 60-180 (ideal 80-100)
CH: 150-500-1,000 (ideal 200-400)
Total Dissolved Solids: max 1,500
1. Pool Calculator shows my CSI at .12 -- there is no mention of that in the Pentair manual, but seems like to get that number in range per Pool Calc I need to add more salt. Should I? Does water with this CSI pose a risk to the heat exchanger or heater in general?
2. I don't see how to figure TDS in the Pool Calculator, nor did I see it in Pool School articles that seemed likely to discuss it (ABCs, Recommended Levels). Anyone know an easy way to calculate this, or is it a separate test I need to run?