Buying a Victorian terrace off Barton Road, or an Edwardian villa in Maxton, or an inter-war semi in Whitfield? The consumer unit is the first thing an EICR-savvy electrician looks at, because it tells you 80% of the story.
Red flag 1: BS 3036 rewireable fuses
The classic old fusebox - a wooden or brown-Bakelite board with 4 to 8 pull-out fuse carriers containing a length of fuse wire. Common on Dover properties that had a 1950s or 1960s rewire and were never upgraded. Zero RCD protection. Zero surge protection. Fuse wire that has probably been "uprated" (thicker wire) at least once. An automatic C2 code on an EICR.
Red flag 2: Wylex plug-in MCB retrofits
A rewireable base fitted with plug-in miniature circuit breakers that replace the fuse carriers. Very common Dover 1980s upgrade. The MCBs are fine as long as they are seated properly, but the base is 1960s vintage and the whole assembly usually has no main-switch RCD. Usually a C2 for the missing RCD coverage.
Red flag 3: Dual-30mA-RCD split-load boards
The 1990s to 2010s standard: a metal or plastic board with two 30mA RCDs, each covering half the final circuits. Compliant when installed, but a single RCD fault takes out half the house at once. Amdt 2:2022 wants individual RCBO per circuit; a split-load board on an EICR usually gets a C3 unless the RCD has failed its timing test, in which case it becomes a C2.
Red flag 4: Combustible enclosure
Amdt 3:2015 to BS 7671 required consumer units in domestic premises to be housed in a non-combustible enclosure - which means metal, not plastic. Older plastic-enclosure boards are permitted if they were compliant when installed, but on an EICR they get a C3. If the plastic is discoloured, cracked, or shows signs of overheating, that flips to C2.
Red flag 5: Undersized main earth
Under BS 7671:2018 the main earth conductor should be at least 16mm on a TN-S supply (which most of the port core is) or 25mm on a TN-C-S (PME) supply. On older Dover properties the main earth is often 6mm or 10mm - undersized. That is a C2 on the EICR.
Red flag 6: Missing SPD
Amdt 2:2022 requires a Type 2 surge protection device on new consumer unit installs unless a documented risk assessment shows it is not needed. On existing installations without SPD the code is C3. On any new install we fit SPD as standard - a £40 part that protects the entire installation from lightning-adjacent transients.
How much does it cost to fix all of this at once?
The single-visit fix is a new 18th Edition consumer unit with tails and main earth upgrade. Typical price on a Victorian terrace: £745 to £895. On a larger house: £895 to £1,150. That single job takes a "definitely fail" EICR to a "clear satisfactory".
Want a fixed-price quote? Send us the details or WhatsApp 07763 100 477.