Question: What does the E4 error mean on my ALPHA GO pump, and how can I fix it?

E4 error on ALPHA GO pumps (ALPHA1 GO and ALPHA2 GO) indicates a dry-running alarm. This means the pump has detected that it is operating without sufficient water, which can cause damage if not corrected. When this happens, the red LED light will turn on, and the pump will automatically stop to protect itself. The ALPHA2 GO event log will record this alarm as Code 57, and it will be seen in the Grundfos GO App.

• The system is not filled with enough liquid.
• Air pockets in the system prevent proper water flow.
• Incorrect commissioning or venting after installation.

How to fix it:

1. Fill the system with the correct amount of liquid according to specifications.
2. Vent the pump to remove air from the system.
   a. For ALPHA2 GO: Use the Grundfos GO app to start a venting cycle (Settings → System and Pump Venting → Set duration to 10 minutes → Start venting).
   b. ALPHA1 GO does not have app-based venting. Venting must be done manually during commissioning by following the steps in its installation manual.
3. Restart the pump and monitor operation to ensure normal flow.

Tip: Always check for leaks or air ingress after refilling the system to prevent future dry-running issues.
Important: Do not ignore this alarm, the pump will not resume operation until the issue is resolved.