BoilerFaultCodesECA F51 Fault Code
The ECA F51 fault code means: your boiler has detected a problem with the temperature sensor for your solar heating system, which is causing the unit to stop operating as a precaution.. It appears on 4 ECA models in our database.
Technical description: PT1000 Solar Sensor Error (blocking) — PT1000 solar sensor may be defective; press Reset; if persists notify ECA authorised service
DIY fix possible
Locate the 'Reset' button on the boiler control panel.Press and hold the button for 3 seconds to clear the fault.If the error returns immediately or frequently, contact a qualified technician to check the sensor wiring.
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ECA models that show the F51 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
ECA F51 fault code information on this page is sourced and cross-checked against the official ECA service / installation manuals for each affected model.
- ECA Confeo Premix HCH manual (PDF)
- ECA Confeo Premix HM manual (PDF)
- ECA Confeo Premix HST manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026