What an electrician checks during a domestic EICR

Helpful video reference. Will Halewood of Electrician TV (JIB Gold Card) walks through the EICR process in a domestic property, showing the visual checks, the testing sequence and how condition codes are applied in practice. His video on the topic is worth watching before your own EICR is carried out, because it sets clear expectations for what the electrician will need access to and how long each phase of the inspection takes.

1. The visual inspection

The electrician begins with a full visual inspection of the installation before any testing starts. This is carried out with the installation energised (live), so the circuits are not switched off at this stage.

The visual inspection covers:

• Consumer unit: The type and condition of the enclosure, the protective devices fitted (MCBs, RCBOs or fuses), whether the board is labelled, whether the main switch operates correctly, and the general condition of the earth bar and connections.
• Earthing and bonding: The main earthing conductor from the consumer unit to the earth terminal on the incoming supply, and the main bonding conductors to gas and water services.
• Accessories: Every socket outlet, light fitting, switch and fused connection unit. The electrician looks for cracked faceplates, signs of overheating, incorrect wiring colours (particularly in older properties where red, black and green wiring may not match the current brown, blue and green and yellow standard), and any accessories that are unsafe or non-compliant.
• Visible wiring: Any wiring that is accessible without lifting floorboards or removing plasterwork. Damaged sheathing, unsupported runs and cables that are too close to heat sources are noted at this stage.

Observations from the visual inspection are recorded on the schedule of inspections (one of the standard forms within the EICR document) before the testing begins.

2. Dead testing: continuity and insulation resistance

The dead tests are carried out with the circuits switched off and isolated. The electrician works through each circuit in turn.

Protective conductor continuity: Each circuit's earth wire is tested to confirm it is continuous from the consumer unit to the furthest accessory. A broken or poorly connected earth wire that passes the visual inspection can be caught here.

Ring final circuit continuity: For ring main circuits (typically ground-floor sockets in older properties), the electrician checks end-to-end continuity on the line, neutral and protective conductors separately, then confirms the ring is correctly wired rather than looped. An incorrectly wired ring (called a figure-of-eight fault) can lead to overloading even when the ring appears to function normally.

Insulation resistance: A high-voltage test (typically 500 V DC) is applied between the line and neutral conductors, and between the line conductor and earth, of each circuit. A healthy circuit returns a reading well above 1 MΩ (megaohm). Low insulation resistance indicates degraded cable sheathing, a damp accessory, or a fault that could cause a shock or fire.

Because the insulation resistance test applies 500 V, the electrician will ask you to ensure that all sensitive electronic equipment (smart home devices, anything with a capacitor-based power supply) is either unplugged or disconnected from the circuit before the test. This is normal and not a sign of a problem.

3. Live testing: RCDs, polarity and earth fault loop impedance

With the circuits re-energised, the electrician carries out the live tests.

RCD operation time: Each RCD (residual current device) and RCBO is tested at half rated tripping current and at rated current using a calibrated test instrument. At rated current (typically 30 mA for domestic installations) the device must trip within 40 ms. A slow-tripping or non-tripping RCD is recorded as a C2 or C1 observation depending on the severity.

Prospective fault current: The electrician measures the worst-case fault current at the consumer unit, which is the current that would flow in the event of a fault directly at that point. This confirms that the protective devices are rated to break the fault safely.

Earth fault loop impedance: On final circuits, the electrician measures the impedance of the fault loop (the path current would follow in a line-to-earth fault). A lower impedance means the circuit breaker operates more quickly in a fault. If the loop impedance is too high for the breaker fitted, there is a risk that the breaker would not disconnect quickly enough to prevent a dangerous touch voltage persisting.

Polarity: A polarity check confirms that the line conductor is connected to the correct terminal in every socket and light fitting tested. Incorrect polarity (sometimes called a crossed live and neutral) means the switch in a lamp or appliance disconnects the neutral rather than the live, leaving the appliance live even when switched off.

4. Condition codes explained

Every observation made during the inspection is assigned one of four codes:

• C1 (Danger present): An immediate risk of injury. Examples include live parts accessible without a tool, a missing earth connection on a metallic accessory, or an RCD that fails to trip at all. The electrician must make the installation safe before leaving the property where it is within their power to do so.
• C2 (Potentially dangerous): Not an immediate risk but a condition that could cause danger if it develops further or under certain circumstances. An undersized protective conductor, an overloaded circuit, or a slow-tripping RCD are typical C2 observations. Remedial work should be arranged promptly.
• C3 (Improvement recommended): The installation is compliant with the standard in force when it was installed, but would benefit from an upgrade to current best practice. No fault and no risk, but something to consider.
• FI (Further investigation): Something requires more investigation to determine whether a fault is present, but that investigation cannot be completed during the current inspection (for example, because it would require lifting floorboards or disconnecting equipment).

The overall classification of the EICR is either Satisfactory (no C1 or C2 codes) or Unsatisfactory (one or more C1 or C2 codes). C3 observations alone do not make a report Unsatisfactory.

5. The EICR report and next steps

At the end of the inspection the electrician signs and issues the completed EICR. The report contains:

• A summary of the installation details (address, description of the installation, number of circuits).
• A schedule of inspections showing the result of each visual check.
• A schedule of circuit details and test results for each circuit tested.
• A list of observations with their condition codes.
• The overall Satisfactory or Unsatisfactory classification.
• The recommended next inspection interval (typically 10 years for an owner-occupied domestic property and 5 years for a rented property).

If the report is Satisfactory, no immediate action is required. File the certificate with your property paperwork.

If the report is Unsatisfactory, the observations with C1 and C2 codes need remedial work. The electrician who carried out the inspection can usually quote for the remedial work, or you can get quotes from other qualified electricians using the EICR as the brief. Once the remedial work is complete, the electrician who carried it out will issue a Minor Works Certificate for each item resolved. The combination of the original EICR and the subsequent certificates brings the installation back to a Satisfactory state.

When to call us

Richard carries out EICR inspections across Sandwich and east Kent for homeowners, landlords and property buyers. The inspection is carried out using calibrated instruments, the report is signed and issued on the day, and any remedial work can be quoted at the same visit to minimise return trips.