BoilerFaultCodesECA 422 Fault Code
The ECA 422 fault code means: your boiler has detected that the water leaving the unit is freezing or at an impossibly low temperature, which has caused it to shut down to prevent damage.. It appears on 1 ECA model in our database.
Technical description: Boiler outlet temperature is not at the desired level (<0 ° C)
DIY fix possible
Check if the condensate discharge pipe (the plastic pipe outside) is frozen and gently thaw it with warm water.Ensure the boiler's power is on and the heating system is not accidentally switched off in freezing weather.Try resetting the boiler if the external temperatures are above freezing.
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ECA models that show the 422 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
ECA 422 fault code information on this page is sourced and cross-checked against the official ECA service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026