F5 Viessmann — Circulation Pump Fault / No Water Flow
At a glance
- Severity
- FAULT STOP
- Domain
- HEATING_SYSTEM
- Reference standard
- EN 15502
What it means
No water circulation in the system due to pump failure.
Probable causes
- Circulation pump mechanically seized
- Air in the system preventing circulation
- Pump starting capacitor worn out
- Impeller fouled with limescale or debris
- Pump bearings seized
Where to start
Check the power supply at the pump terminals. Is voltage present?
Full guided diagnosis in the app
The diagnostic tree for this fault has 7 guided steps with measurements, checks and resolutions. You'll find it in HVACIQ, one of the five IndexOS apps: free, works offline.
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