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Consumer Units5 min read25 January 2025

Signs Your Consumer Unit (Fuse Box) Needs Replacing

Your consumer unit is the heart of your home's electrics. Here are the key signs that it's time for an upgrade to a modern, safer unit.

The consumer unit — often called the fuse box — is the control centre of your home's electrical system. It distributes electricity to all circuits and provides protection against faults and overloads. An outdated consumer unit is one of the most common electrical hazards in UK homes.


How Old Is Your Consumer Unit?


If your consumer unit was installed before the late 1990s, it is almost certainly due for replacement. Here's how consumer units have evolved:


  • Pre-1960s — Old round rewirable fuses, often in a wooden or Bakelite box
  • 1960s–1980s — Cartridge fuse holders, still no RCD protection
  • 1980s–2000s — Early MCB boards, often with a single RCD
  • 2000s–present — Dual RCD or RCBO boards, meeting BS 7671:2018

Key Warning Signs


1. You Have Rewirable Fuses


If your board has fuses that need replacing with wire, it is significantly outdated and provides no protection against electric shock. These should be upgraded immediately.


2. No RCD Protection


RCDs (Residual Current Devices) cut the power in milliseconds if they detect a fault — potentially saving your life. Pre-2000s boards often had no RCD or just a single RCD covering part of the installation. Current regulations require RCD protection on most circuits.


3. The Board Is Made of Combustible Material


Consumer units installed before 2016 often had plastic cases. Current regulations require consumer units in domestic properties to have metal enclosures to prevent fire spread.


4. Frequent Tripping


If your fuses or MCBs trip regularly, this can indicate an overloaded or faulty installation that an upgraded board and wiring assessment could resolve.


5. Burning Smell or Scorch Marks


Any burning smell or discolouration around your consumer unit is a serious warning sign. Switch off at the mains and call an electrician immediately.


6. You're Planning Home Improvements


If you're adding an extension, EV charger, or significant new loads, your existing consumer unit may not have capacity — making an upgrade a practical necessity.


What Does a Consumer Unit Upgrade Involve?


Onyx Electrical Solutions will replace your existing board with a modern dual-RCD or full-RCBO consumer unit. We test all existing circuits, resolve any defects found, and provide certification on completion. Most consumer unit upgrades are completed in a single day.


Call 07000 000000 for a free quote across Greater Manchester.

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