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EICR Observation Builder

Describe a fault and get the correct C1/C2/C3 code with BS 7671 regulation references

Smart Engine
Describe the Fault
Enter a description of the electrical fault or observation

One defect per line (max 3). Be specific about location for better results.

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Privacy Notice: Please do not enter client names, addresses, or other personal information.

Top 10 Common EICR Faults & Codes
Quick reference for frequently encountered observations
FaultCodeRegulation
Exposed live parts at accessory
C1
416.2.1
Damaged socket outlet
C1
553.1.201
Protective conductor missing
C2
411.4.2
Main bonding conductor inadequate
C2
544.1.1
Zs exceeds maximum permitted value
C2
411.4.4
Incorrect polarity identified
C2
643.6
Lack of RCD protection to socket circuits
C3
411.3.3
Circuit identification not provided
C3
514.8.1
Consumer unit enclosure non-compliant
C3
421.1.201
Unable to gain access for testing
FI
529.3
About the Observation Builder
Understanding EICR codes and how to classify observations

The TestFast Observation Builder uses a smart engine trained on thousands of electrical observations to help you classify faults correctly. It provides the appropriate code along with BS 7671 regulation references.

C1 - Danger Present

Immediate risk of injury. Installation must not be energized until the fault is rectified.

C2 - Potentially Dangerous

Risk of injury may arise. Urgent remedial action is required.

C3 - Improvement Recommended

No immediate danger, but the installation would benefit from improvement.

FI - Further Investigation

The fault could not be fully assessed and requires further investigation without delay.

Related Tools

Max Zs Calculator
BS 7671 loop impedance
Cable Size Calculator
SWA sizing with volt drop

Ready for the Full Experience?

These free tools are just a taste. TestFast automates your entire EICR workflow with the observation builder, handwriting & consumer unit OCR, and instant certificate generation.

Start Today For Free
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Product

  • Home
  • Features
  • Pricing
  • How It Works
  • FAQ

Software

  • EICR Software
  • Electrical Certificate Software
  • Electrical Testing Software
  • Electrical Contractor Software
  • EICR Certificate Software
  • Best EICR Software
  • Free EICR Software
  • Electrical Certificate App
  • Electrical Certificate Software Pricing

Free Tools

  • All Free Tools
  • 2391-52 Mock Exam
  • Max Zs Calculator
  • Voltage Drop & Cable Size Calculator
  • Observation Builder
  • Max Demand Calculator
  • R1+R2 & Ring Continuity Calculator
  • PFC Calculator

Resources

  • Blog
  • Press
  • Partners
  • Testimonials
  • About Us

Legal

  • Privacy Policy
  • Terms of Service
  • Sitemap
Try TestFast Now

© 2026 TestFast. All rights reserved.