Grundfos ALPHA2 GO Pumps
17 fault codes documented
E3 / Code 132 — Pump configuration corrupted or missing
The warning and alarm symbol flashes red, the display shows error code E3, and the pump stops. This means the pump's internal configuration file is corrupted or missing.
E9 / Code 25 — Incorrect PWM configuration
The warning and alarm symbol flashes yellow, and the pump continues to run. This means the pump is receiving a signal via the PWM input, but the PWM configuration is either missing or incomplete.
Code 35 — Air in media (Grundfos GO only)
This fault is not shown on the pump's operating panel but is logged and can only be seen in the Grundfos GO app. It indicates that there is air present in the pump and/or the system.
E3 / Code 4 — Overvoltage
The warning and alarm symbol flashes red, the display shows error code E3, and the pump stops. This means the electrical supply voltage to the pump is too high.
E2 / Code 40 — Undervoltage
The warning and alarm symbol flashes red, the display shows error code E2, and the pump stops. This means the electrical supply voltage to the pump is too low.
E3 / Code 43 — Forced pumping detected
The warning and alarm symbol is permanently yellow, the display shows error code E3, and the pump continues to run. This indicates that other pumps or external sources are creating an unintended flow through this pump.
E1 / Code 51 — Blocked motor
The warning and alarm symbol flashes red, the display shows error code E1, and the pump stops. This indicates that the pump's motor is blocked.
E4 / Code 57 — Dry running detected
The warning and alarm symbol flashes red, the display shows error code E4, and the pump stops. This indicates that water is missing in the system or the system pressure is too low, causing the pump to run dry.
E3 / Code 72 — Internal fault
The warning and alarm symbol flashes red, the display shows error code E3, and the pump stops. This indicates an unspecific internal fault within the pump.
E3 / Code 76 — Internal fault
The warning and alarm symbol flashes red, the display shows error code E3, and the pump stops. This indicates an unspecific internal fault within the pump.
E3 / Code 85 — Internal fault
The warning and alarm symbol flashes red, the display shows error code E3, and the pump stops. This indicates an unspecific internal fault within the pump.
Code 25 — Incorrect PWM configuration
Error Code 25 indicates that the Pulse Width Modulation (PWM) signal setup, used to control the pump's speed and flow rate, is incorrectly configured. This often occurs during initial installation or when replacing an existing pump.
Insufficient heat in heating system — Possibly due to Night Setback
If your heating system is not providing adequate heat, one possible cause is the 'Night Setback' function being active. This feature automatically reduces pump activity during certain periods to save energy.
Noise in the system — Flow too high or air present
The pump system is producing audible noise during operation. This can be caused by excessive flow or air trapped within the system.
PWM feedback signal at 90% — Possible blocked rotor
The pump's PWM feedback signal, which provides real-time operating status, indicates a 90% duty cycle. This specific feedback usually triggers a warning, suggesting that the pump's rotor might be blocked or obstructed.
Red LED lit — Pump alarm, pump has stopped operating
When the warning and alarm symbol on the operating panel turns red, the pump has encountered a critical alarm and stops operating completely. All mode, speed, and unit LEDs are switched off. Immediate action is required to resolve the issue.
Yellow LED lit — Pump warning, still operating but not as expected
When the warning and alarm symbol on the operating panel turns yellow, the pump is in a warning state. It continues to run, but its performance may not be optimal, potentially leading to issues like insufficient heating. An error code will alternate on the display.