Warning 88 – Internal sensor fault
• A yellow Grundfos Eye indicates the warning.
The pump will continue to operate.
• The internal sensor is either blocked due to impurities in
the media, or the communication from the sensor is faulty.
• Make sure the sensor and the measuring channels
in the pump house are not blocked.
• Replace the sensor if the error continues or disable the alarm
in the Settings menu if the reading is not needed and the
product is running in open loop control (constant curve).
Warning 77 – Multipump communication
• A yellow Grundfos Eye indicates the warning. Both pumps in
the multipump system will continue to operate according to
their local settings.
• The error is caused by the two pumps losing their
radio connection.
• The pumps will search for each other and pair automatically
again after reestablishing connection.
• Make sure both pumps are supplied with power. If the
multipump system is not desired, dissolve it via
the Assist menu on the pump display.
Alarm 72 – Internal fault
• A red Grundfos Eye indicates the alarm.
The pump stops but will automatically try to restart.
• There might be turbine ow in the application, forcing a ow through the pump.
• Irregularities in the voltage supply can also cause this alarm.
• Check the application and take necessary measures to avoid turbine ow.
• If the alarm continues, contact Grundfos Service.
Alarm 51 – Blocked pump
• A red Grundfos Eye indicates the alarm.
The pump stops but will automatically try to restart.
• Make sure the rotor is not physically blocked
(e.g. after being turned o for extended periods of time).
• If the error continues, contact Grundfos Service.
Alarm 10 – Internal fault
• A red Grundfos Eye indicates the alarm.
The pump stops but will automatically try to restart.
• This error can occur if dierent print circuit boards in the pump have lost
connection to each other.
• Please contact Grundfos Service.
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Alarms and warnings
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