I have a 3800 that keeps showing err3 (freez sensor) despite replacing with a new TS5L sensor. It will not allow calibration (after entering Program and going to 3rd step - Adj 3 "Enter correct air
temperature.." . the up/down temp control does nothing). I do a lot of electronics repair, microcontroller work, etc and I am sure I could diagnose and repair the control board if I could only find a schematic and parts list. Pentair customer service doesn't respond to my question except to say contact a local dealer. The local dealers want me to replace the board for $500+.