Jandy AquaLink freeze guard
I am in Livermore CA, 50 miles east of San Francisco. Our air temperature goes as low as 28 F some nights, but the water in my pool never gets below about 42 F. The freeze guard comes on at 34 F air temperature (lowest possible setting) and the filter and waterfall pumps run all night. Together they draw about 5 kilowatts. We pay 44 cents per kWh, so it costs about $20 each night they run.
It seems that the freeze guard should be necessary if the WATER temperature in the pool machinery approaches freezing, not the AIR temperature. I could swap the connections of the water temperature and air temperature sensors at the AquaLink, so that the freeze guard will come on if the WATER temperature goes below 34 F, rather than the AIR temperature. That should save a lot of electricity, but surely somebody has thought of this before and there is a good reason Jandy didn't design it that way. Can anybody explain this to me? Thank you.