Question: What does the E3 error mean on my ALPHA GO pump, and how can I fix it?

E3 error on ALPHA GO pumps (including ALPHA1 GO and ALPHA2 GO) can indicate two different situations, depending on the LED color:

Case 1: Yellow LED + E3
If the yellow LED light is on with error E3 (Code 43 in Grundfos GO App) the pump is experiencing forced pumping. This means water is flowing through the pump even though it is switched off. This usually happens because other pumps or external sources in the system create flow through the inactive pump. Remedy:

1. Check the system for the correct position of the non-return valves.
2. Check the system for defective non-return valves and replace the valves if necessary.

Important: This is a warning, not an alarm, the pump is not damaged, but the system may not operate as intended until the issue is resolved.

Case 2: Red LED + E3
If the red LED light is on with error E3, the pump has stopped due to:

1. Overvoltage (Code 4 in Grundfos GO App)
   The supply voltage to the pump is too high. Make sure that the power supply is within the specified range.
2. Internal Fault (Code 72, code 76 and code 85 in Grundfos GO App)
   Replace the pump or contact Grundfos.
3. Pump configuration corrupted or missing (Code 132 in Grundfos GO App)
   The configuration file has been corrupted or is missing. Reconnect with Grundfos GO and repeat the configuration.

The specific codes for E3 errors can be seen in the event log in the Grundfos GO app, this is however only applicable for ALPHA2 GO circulator pumps.