Pentair IntelliFlo / IntelliPro VS or VSF pump display shows “ERR” and pump will not run or stops shortly after starting.

Safety first: Turn off power at the pool sub‑panel breaker and verify with a non‑contact voltage tester before touching any wiring.

• Step 1 – Power cycle the pump: Turn the pump breaker OFF for 2–3 minutes, then back ON. Try starting the pump from the keypad. If ERR clears and does not return, monitor operation.
• Step 2 – Check supply voltage: Using a multimeter (by a qualified person), verify that the line voltage at the pump’s L1/L2 terminals matches the nameplate (typically 230 V ±10%). Low or fluctuating voltage can trigger ERR.
• Step 3 – Inspect wiring and terminals: With power OFF, remove the drive cover and inspect the incoming power terminals for heat damage, corrosion, or loose screws. Tighten loose connections and clean light corrosion. Replace any burnt wiring.
• Step 4 – Check for water intrusion: Inspect the drive/control housing gasket and cover. Look for moisture, condensation, or corrosion on the control board. If water is present, the drive assembly is likely compromised and should be replaced.
• Step 5 – Isolate external controls: Disconnect any RS‑485 communication cable (from Pentair EasyTouch/IntelliCenter/IntelliTouch) and any external relay or automation wiring. Try running the pump locally from the keypad. If ERR disappears, the issue may be with the automation system or wiring.
• Step 6 – Replace drive if persistent: If ERR returns immediately with proper voltage and dry electronics, the internal drive/control module is likely defective and should be replaced as an assembly.

When to call a professional: If you are not comfortable working around high voltage or if ERR persists after basic checks, contact a Pentair‑qualified pool technician or electrician.