Hello. I do not have a Solar Water heater system. My pool guy states I need to replace my water temp sensor. I believe that Part #520272. There is a sensor hanging down from the bottom of the control cabinet. Could that be sensor Part #522101? If I have to replace one of them, minus well replace them both. Now, contacting Pentair, they said to use Part #520272 (same as for water temp) for the air temp sensor. Do you agree? Very confusing. Thank you for any comments.