Pump display shows E05 and motor speed cannot be adjusted; unit may run at fixed low or high speed only.

Safety First: Disconnect power at the breaker before opening the drive or control housing.

• Inspect tachometer wiring: On Rheem variable‑speed models, locate the low‑voltage harness between the motor and control board. Unplug and inspect for corrosion, bent pins, or broken conductors. Clean contacts and reseat firmly.
• Check for physical damage: Look for crushed or abraded control cables along the conduit or cable run. Replace any damaged harnesses with Rheem‑approved parts.
• Reset the drive: With power off for 2–3 minutes, restore power and perform a factory reset of the controller per the Rheem manual. Reprogram speeds and schedules.
• Test at different speeds: Attempt to run the pump at several preset speeds. If E05 appears immediately or speed feedback is erratic, the tach sensor or drive is likely defective.
• Replace motor/drive assembly: On many Rheem variable‑speed pumps, the tach sensor is integrated into the motor/drive. Replace the complete motor/drive assembly if the sensor cannot be serviced separately.