I updated the code yesterday, and looking at the output log, everything seems to be functioning as expected. I think the temp probe might be getting some irregular readings from time to time due to it's placement. I see the backup heater is turning on occasionally, but just for a second or two, which leads me to believe the temp probe is reading below 78.8 momentarily. The temp probe is currently in the return pump section of sump. This is also where ATO water and ALK/CAL dosing fluid is added. So this might be messing with temp in that section of the sump. Suggestions on better placement for the temp probe? Or other solution to stabilize the on/off activity of heaters?