ESYS has expertise with this multi-loop controller. It has been used in various applications; the one it was designed for is boiler control. The application that we used it on (and serviced it on) was CEMS (continuous emissions monitoring).
On the CEMS application, the controller handled analog rescaling (for daily automatic re-calibration offsets), solenoid valve control, and some limited threshold/alarm logic.
If you’re looking for a quick fix – try replacing the battery. That could cure a whole host of problems.