B1
Nibe
Heating circulation pump fault
B1 alarm, no circulation in heating system, radiators cold
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Seized circulation pump, air‑locked pump, blocked pump or filter, failed pump electronics
How to Fix / Troubleshooting
Safety: Turn off power and close isolation valves before working on pumps. Risk of hot water release.
- Check pump status in menu: Many Nibe units show pump speed and status. If the control says the pump is running but you feel no vibration, the pump may be seized.
- Bleed the pump: Some Nibe circulation pumps have a bleed screw. With power off and a cloth ready, open the screw slightly to release air and a small amount of water, then close.
- Free a stuck rotor: If accessible, remove the pump motor head and gently turn the rotor with a screwdriver to free it. Refit and test.
- Clean system filter: Clean any inline filter or strainer on the heating circuit to restore flow.
If the B1 alarm persists, the pump module may need replacement.
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Repair Difficulty
Medium
3/5
Required Part
Heating Circulation Pump
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