Failed EICR in Cardiff: what C1, C2 and C3 actually mean
Got a failed EICR in Cardiff? Plain-English guide to C1, C2, C3 and FI codes plus fixed-price remedials.
Owners and landlords across CF10–CF24 ask about this in roughly equal numbers, for slightly different reasons. Opening an EICR and seeing red "Unsatisfactory" with a list of C1, C2, C3 codes is alarming — most of the time it shouldn't be. eicr diagnostics tends to be judged on the finish, but the part that matters sits behind the wall and only shows up in the readings. If it turns out not to apply here, you will be told that plainly. Anything we recommend is tied to a specific finding rather than to a general principle. Around Cardiff Council that is a familiar finding rather than an alarming one. Searching "eicr diagnostics Cardiff" from a Cardiff address usually means you want a straight answer before you want a salesperson.
- FI = further investigation needed It is recorded on the paperwork.
- Where it applies: fixed-price remedials within the week
- C1 = danger present, fix immediately — the point at which a small job can turn into a larger one.
- C2 = potentially dangerous, fix urgently. We would rather find this on a planned visit than an urgent one.
- C3 = improvement recommended (not a fail) — noted, measured, then explained in plain terms.
What's different about Cardiff
The single most common C2 we see across Cardiff is missing RCD protection on socket circuits — usually because many older Cardiff properties still run on rewireable BS 3036 fuse boxes that no longer meet 18th Edition requirements. It is recorded on the paperwork.
Where it applies: C3 codes are not a fail and don't require any action — but a previous inspector may have written one up as if it were. We re-grade fairly.
Left alone, FI = further investigation needed rarely improves on its own.
Fixed-price remedials within the week rarely travels alone on an installation of that vintage.
How we'd do it
- 1ReviewWe send us the failed PDF before deciding what, if anything, needs replacing.
- 2QuoteWhere it applies: fixed price for each code that actually needs work.
- 3FixMost remedials cleared in a single visit closes the job out cleanly.
- 4Re-issueSatisfactory EICR re-issued on completion. Confirmed before pricing.
Common questions
Does C3 fail the EICR?
No — C3 is improvement only. The EICR is still satisfactory.
How far in advance should I book?
For non-urgent work, a week or so gives the most choice of slots across CF10–CF24.
Is older wiring automatically a problem?
No. Plenty of older Cardiff installations test well. Age is a reason to check, not a verdict.
Can the work be staged?
Often, yes. Where the findings allow it we prioritise what affects safety and leave the rest to be planned.
Do you cover Cardiff for eicr diagnostics?
Yes — Cardiff and the surrounding CF10–CF24 postcodes are part of our regular working area, including Penarth and Caerphilly, and Cardiff Council notification is handled by us where the work requires it. Worth knowing before booking.
Do you deal with the paperwork for the council?
Where notification is required, it is submitted to Cardiff Council as part of the job.
We would rather answer a question than sell you a visit you do not need. Ask first. We cover Cardiff and the CF10–CF24 postcodes, including Penarth, for eicr diagnostics. Tell us what document you have been asked for and by whom, and we will confirm exactly which one applies. We cover Cardiff and the CF10–CF24 postcodes, including Caerphilly, for eicr diagnostics.
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