| Parameter | Meaning | Typical range | |-----------|-----------------------------|------------------------| | P | Proportional band | 0–999 (PID mode) | | I | Integral time | 0–999 sec | | D | Derivative time | 0–999 sec | | SC | Sensor correction offset | -50 to +50°C/°F | | HY (or Hy) | Hysteresis (on/off mode) | 0.1–50°C | | Ctl (or C) | Control mode (0=on/off, 1=PID, 2=heat/cool) | | Sn (or Sen) | Sensor type (K, J, PT100) | | | Problem | Likely cause | |--------------------------|--------------------------------------| | No display | Wrong power / blown fuse / wiring | | Shows “HHH” or “LLL” | Sensor open, short, or wrong type | | Temperature not stable | Incorrect PID or hysteresis settings | | Relay clicks but no heat | Relay wiring wrong or load too high | Need the exact original manual? If you can share the full model code from the sticker (e.g., Caho H481-PID-K-AC), and a photo of the terminal diagram , I can help identify the exact pinout and parameter list.