Grundfos MAGNA3 Circulator Pumps
21 fault codes documented
Alarm 10 — Communication fault
There is a communication fault between different electronic parts within the pump. The pump has stopped due to this alarm.
Alarm 29 — Forced pumping
Other pumps or external sources are forcing flow through this pump, even when it is stopped and switched off. The pump has stopped due to this alarm. The Grundfos Eye might show a light indicating forced-pumping mode.
Alarm 40 or 75 — Undervoltage
The electrical supply voltage reaching the pump is too low, which can prevent proper operation and has caused the pump to stop.
Alarm 51 — Pump is blocked
The pump's internal components are blocked, preventing the pump from rotating. This alarm has caused the pump to stop.
Alarm 57 — Dry running
There is no water present at the pump's inlet, or the water contains too much air. This alarm has caused the pump to stop and does not automatically reset.
Alarm 64 — High motor temperature
The temperature within the stator windings of the pump's motor has become too high, leading to an alarm and the pump stopping. This alarm does not automatically reset.
Alarm 72 or 155 — Internal fault
An internal fault has occurred within the pump's electronics. Irregularities in the voltage supply or turbine flow can sometimes trigger alarm 72. The pump has stopped.
Alarm 74 — Overvoltage
The electrical supply voltage to the pump is too high, which can damage the electronics and has caused the pump to stop.
Warning 77 — Twin-head pump communication fault
The communication link between the two pump heads in a twin-head pump configuration has been disturbed or completely broken. This is a warning and does not activate the alarm relay.
Warning 84 or 157 — Internal fault
A fault has been detected within the pump's electronics. This is a warning and does not activate the alarm relay, indicating a less critical issue than an alarm.
Warning 88 — Internal sensor fault
The pump is receiving a signal from its internal sensor that is outside the normal operating range. This is a warning and does not activate the alarm relay.
Warning 93 — External sensor fault
The pump is receiving a signal from an external sensor that falls outside its normal operating range. This is a warning and does not activate the alarm relay.
Alarm signal activated — Pump has registered a fault
The pump's signal relay (Relay 2 by factory default) is activated, indicating that the Grundfos MAGNA3 pump has registered an internal fault. This signal is typically connected to an external fault indicator or a building management system.
Cavitation noise — Pump damage risk
An audible noise from the pump indicates cavitation, which occurs when the minimum required inlet pressure is not met. This condition can damage the pump bearings and reduce its performance.
Middle green light flashing continuously — Communication attempt from Grundfos GO or another pump
The green indicator light in the middle of the Grundfos Eye flashes continuously. This signifies that Grundfos GO or another pump is trying to establish communication with this pump.
Two opposite green lights solid — Power is on, but pump is not running
The Grundfos Eye shows two opposite green lights are continuously lit. This indicates that the pump is receiving power but is not operating.
Motor hunting up and down or measured value fluctuates — Controller instability
The Grundfos MAGNA3 pump motor's speed fluctuates erratically (referred to as 'hunting'), or the measured values on the display become unstable. This indicates that the pump's PI controller settings (gain and integral time) are not optimally tuned for the specific system, leading to operational instability.
No lights on Grundfos Eye — Power is off or pump is not running
The Grundfos Eye on the control panel shows no lights, indicating that the pump has no power or is not currently operating.
Two opposite red lights flashing — Alarm, pump has stopped
The Grundfos Eye shows two opposite red lights flashing at the same time. This indicates a critical alarm condition has been detected and the pump has stopped.
One yellow light running — Warning, pump is operating with an issue
The Grundfos Eye displays a single yellow light moving in the direction of the pump's rotation. This signifies that the pump is currently running but a warning condition has been detected.
One yellow light solid — Warning, pump has stopped
A single yellow indicator light remains constantly on. This indicates that a warning condition has occurred and the pump has ceased operation.