Grundfos COMFORT 10-16 - Fault Finding and Troubleshooting; General Faults and Errors

8. Fault finding
8.1 General faults and errors
8.1.1 The pump is not running
The pump has stopped operating and no LEDs are lit.
Cause Remedy
The power supply has been
interrupted.
• Restore the electrical connection.
The rotor is blocked by deposits or
foreign bodies.
• Clean the parts that are in direct
contact with water.
A rotor bearing is either worn or
faulty.
• Replace the motor.
There is air in the recirculation
system.
• Vent the circulation pipe.
The motor is faulty. • Replace the motor.
8.1.2 Constant supply of hot water but the pump is not running
Cause Remedy
The non-return valve is constantly
open (gravity circulation).
• Fit a non-return valve downstream
of the pump.
8.1.3 The pump is repeatedly starting and stopping
Cause Remedy
There is air in the pump, and dry-
running protection is active.
• Vent the circulation pipe.
8.1.4 Noisy pump
Cause Remedy
There is air in the pump housing, and
dry-running protection is active.
• Vent the circulation pipe.
The rotor bearing is worn or faulty. • Replace the motor.
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English (US)