EICR Observation Codes Explained: C1, C2, C3, and FI

What are EICR observation codes?

When an electrician carries out an Electrical Installation Condition Report (EICR) under BS 7671, every deficiency found gets classified with a code. These codes determine whether the installation passes or fails — and what action the building owner must take.

Getting these codes wrong creates real problems: wrong classification on a report can mean unnecessary remedial work, legal exposure, or — worse — a dangerous installation signed off as satisfactory.

The four classification codes

C1 — Danger present

Risk of injury exists. The installation should be made safe immediately. An EICR with a C1 observation is always classified as Unsatisfactory.

Examples:

• Exposed live parts accessible without tools
• Missing earthing conductor to an appliance
• Burnt-out consumer unit with signs of arcing

What happens next: The electrician may isolate the affected circuit on site. Remedial work is urgent.

C2 — Potentially dangerous

Risk of injury may arise. Urgent remedial action is required. An EICR with a C2 observation is also classified as Unsatisfactory.

Examples:

• Missing RCD protection on socket circuits (post-2008 installations)
• Inadequate bonding to gas/water services
• Insulation resistance below acceptable limits

What happens next: Remedial work should be carried out as soon as possible, but the circuit doesn't necessarily need immediate isolation.

C3 — Improvement recommended

Not compliant with the current edition of BS 7671, but no immediate danger. This does not make the EICR unsatisfactory.

Examples:

• Lack of RCD protection on a pre-2008 installation where it wasn't required at the time
• Consumer unit not to current fire-resistance standard
• Absence of surge protection (now required under Amendment 2)

What happens next: The building owner is advised to consider improvement, but there's no legal obligation to act.

FI — Further investigation required

The inspector cannot fully assess the condition of part of the installation without further work (e.g., removing covers, testing circuits that were isolated, accessing areas behind fixed furniture).

An FI observation does not make the EICR unsatisfactory on its own, but it means the inspection is incomplete.

What happens next: A separate visit or further investigation is arranged. Once complete, the FI may be reclassified as C1, C2, C3, or cleared.

How codes affect the overall EICR result

| Codes present | Overall result | |---|---| | C3 only | Satisfactory | | FI only | Satisfactory (but incomplete) | | Any C1 or C2 | Unsatisfactory |

A single C1 or C2 observation overrides everything else — the installation fails regardless of how many items pass.

Common mistakes contractors make

1. Classifying old but safe installations as C2 — if it was compliant when installed and isn't dangerous now, C3 is correct
2. Using C3 for genuine hazards — if there's a real risk of injury, it must be C1 or C2
3. Issuing FI and never following up — technically valid, but leaves the report incomplete and the customer exposed
4. Forgetting that C1/C2 auto-fail the EICR — no manual override should be possible

How Opscel handles this

Opscel enforces the BS 7671 classification rules at the system level:

• Can't mark an EICR as "Satisfactory" if C1 or C2 observations are present
• Defect logging links directly to remedial quotes — log a C2, generate a quote from the same screen
• Complete audit trail from observation through remediation, with linked Minor Works certificates
• Zs auto-lookup validates readings against BS 7671 Table 41.4 so borderline values get flagged before the engineer signs off

The system prevents the most common compliance mistakes before they leave the site.

Summary

| Code | Severity | EICR outcome | Action required | |---|---|---|---| | C1 | Danger present | Unsatisfactory | Immediate | | C2 | Potentially dangerous | Unsatisfactory | Urgent | | C3 | Improvement recommended | Satisfactory | Advisory | | FI | Further investigation | Satisfactory (incomplete) | Follow-up visit |

Understanding these codes isn't optional — they're the difference between a defensible certificate and a liability.