EICR Defect Classification Guidelines

Electrical Installation Condition Reports (EICRs) are formal statutory documents used to assess the safety of an existing electrical installation against the current version of the IET Wiring Regulations (BS 7671). For electrical apprentices and qualified supervisors, accurately classifying defects is the most critical skill required to ensure public safety.

The Coding System Explained

During an inspection, any deviations from the regulations that impact safety must be recorded and assigned a classification code. These codes determine whether the installation is deemed "Satisfactory" or "Unsatisfactory".

• Code C1 (Danger Present): There is an immediate threat to life. Live parts are accessible to human touch, or the fundamental protection against electric shock has completely failed. The inspector must take immediate action to make the installation safe before leaving the site. Result: Unsatisfactory.
• Code C2 (Potentially Dangerous): The defect does not pose an immediate danger, but could become lethal under fault conditions or foreseeable future circumstances. Examples include an absence of earthing on a circuit, or high Earth Fault Loop Impedance (Zs) values preventing a breaker from tripping. Result: Unsatisfactory.
• Code C3 (Improvement Recommended): The installation does not pose a danger, but it does not comply with the latest modern enhancements of BS 7671. Examples include older plastic consumer units located outside of escape routes, or missing colour identification sleeving. Result: Satisfactory.
• FI (Further Investigation): Used when an inspector suspects a serious defect (C1 or C2) exists, but requires more intrusive testing or dismantling to confirm it, which falls outside the agreed scope of the standard EICR. Result: Unsatisfactory.

Best Practice Guide 4 (BPG4)

Electrical Safety First (ESF) publishes Best Practice Guide 4, an industry-recognized consensus document that provides standardized coding examples for hundreds of common faults. This TMUK Group practice lab utilizes real-world scenarios mapped directly to BPG4 and BS 7671:2018+A3:2024 to train engineers in maintaining consistency across the industry.