BoilerFaultCodesChaffoteaux 7.iv Fault Code
Also written as 7IV — same fault.
The Chaffoteaux 7.iv fault code means: your boiler is leaking internally between the heating and hot water systems, causing water to pour out of the safety pipe outside.. It appears on 2 Chaffoteaux models in our database.
Technical description: Safety valve discharges - Secondary heat exchanger (water to water) internal water leak
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Chaffoteaux models that show the 7.iv fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Chaffoteaux 7.iv fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026