ECA 98 Fault Code
The ECA 98 fault code means: your boiler's internal computer is having trouble communicating with an add-on control component, which usually means the system cannot manage your heating or hot water correctly.. It appears on 1 ECA model in our database.
Technical description: Additional module 1, error
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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ECA models that show the 98 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
ECA 98 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