IntelliFlo / IntelliPro VS or VSF display shows “Comm Error” or automation panel reports communication loss with the pump.

Safety first: Turn off power to both the pump and automation panel before working on low‑voltage wiring.

• Step 1 – Inspect RS‑485 cable: Locate the green 4‑pin RS‑485 connector at the pump drive and at the automation panel. Ensure the same color wires go to the same terminals (A to A, B to B, +15, GND) on both ends.
• Step 2 – Tighten terminals: Gently tug each wire to confirm it is secure. Re‑strip and re‑terminate any loose or corroded conductors.
• Step 3 – Check cable routing: Avoid running the RS‑485 cable parallel and close to high‑voltage lines. If necessary, reroute or use shielded twisted pair cable.
• Step 4 – Test local control: Disconnect the RS‑485 cable at the pump and attempt to control the pump from its keypad. If it works locally, the issue is likely in the automation system or cable.
• Step 5 – Replace cable or boards as needed: If wiring is correct but Comm Error persists, try a temporary new cable. If still failing, the RS‑485 port on the drive or automation main board may be defective and require replacement.

Note: After restoring communication, re‑address and configure the pump in the automation system per Pentair instructions.