The Ultimate Guide to Changing a Consumer Unit

Jan 25, 2024


Welcome to the ultimate guide on changing a consumer unit brought to you by Prometheus Electrical. As experts in the field of lighting fixtures & equipment and electricians, we understand the importance of providing top-notch information that helps you make informed decisions. In this comprehensive guide, we will walk you through the process of changing a consumer unit step by step, ensuring your safety and peace of mind. Let's get started!

Understanding Consumer Units

Before we dive into the detailed steps of changing a consumer unit, let's first understand what a consumer unit is and why you may need to replace it. A consumer unit, also known as a fuse box or distribution board, is a crucial component of every electrical system. It controls and distributes electricity to different circuits within your premises, ensuring safety and protecting against electrical faults.

Over time, consumer units may become outdated, and their components can wear out or become obsolete. This may lead to safety concerns or inadequate electrical supply to meet modern-day demands. As a result, it is essential to consider changing your consumer unit to ensure the utmost safety and efficiency for your electrical system.

Step-by-Step Guide to Changing a Consumer Unit

Step 1: Preliminary Preparations

Before you start changing your consumer unit, there are a few preparatory steps to ensure a smooth and safe process:

  • Gather the required tools: To successfully change a consumer unit, you will need a range of tools, including a screwdriver, wire cutters, pliers, insulation tape, and a voltage tester. Having these tools ready beforehand will save you time and effort.
  • Turn off the electricity supply: Your safety is of utmost importance during any electrical work. Locate your main electrical supply switch and turn it off to cut off the power supply to your premises.
  • Make a note of your circuit configurations: Take the time to understand and document the existing circuit configurations in your old consumer unit. This will help you ensure correct connections when installing the new unit.

Step 2: Disconnecting the Existing Unit

Now that you're fully prepared, it's time to disconnect the existing consumer unit. Follow these steps:

  1. Remove the unit cover: Use a screwdriver to carefully remove the cover of your old consumer unit. Set the cover aside in a safe place to avoid damage.
  2. Test for voltage presence: Take your voltage tester and ensure that there is no power running through the unit. This step is crucial for your safety.
  3. Disconnect the cables: One by one, disconnect the cables from the breakers in your old consumer unit. Remember to label or make note of the corresponding circuit for each cable.
  4. Remove the old unit: Once all the cables are disconnected, carefully remove the old consumer unit from its base. Keep it aside for safe disposal or as per local regulations.

Step 3: Installing the New Consumer Unit

With your old consumer unit safely disconnected, let's move on to installing the new one:

  1. Position the new unit: Place the new consumer unit in the same position as the old one, ensuring a secure and level fit.
  2. Prepare the wiring: Strip the ends of the cables that were disconnected from the old unit and trim them if necessary. This step ensures clean and proper connections.
  3. Connect the cables: Following your earlier notes or labels, reconnect each cable to the corresponding breaker in the new consumer unit. Double-check that all connections are secure and tight.
  4. Secure the unit: Once all the cables are connected, secure the new consumer unit in place using the manufacturer's provided screws or fixings.

Step 4: Final Testing and Safety Check

With the new consumer unit installed, it's time to ensure everything is functioning safely and correctly:

  • Restore electricity supply: Carefully turn on your main electrical supply switch to restore power to your premises.
  • Test each circuit: Go through each circuit and check if electrical appliances and fixtures are functioning as expected. If any anomalies are found, consult a qualified electrician.
  • Tighten and secure: Double-check all connections, screws, and fixings to ensure that everything is tightly secured.
  • Dispose of the old unit: If local regulations permit, dispose of the old consumer unit safely or recycle it through appropriate channels.


Congratulations! You have successfully changed your consumer unit and ensured the safety and efficiency of your electrical system. We hope this comprehensive guide from Prometheus Electrical has provided you with the knowledge and confidence to undertake this task.

Always remember that electrical work can be complex and potentially hazardous if not done properly. If you feel unsure or uncomfortable, it is highly recommended to seek the assistance of a qualified electrician. Your safety should always be the top priority.

At Prometheus Electrical, we pride ourselves on delivering exceptional service and expertise in the field of lighting fixtures & equipment and electrician services. Should you require any further assistance or have questions, please feel free to reach out to us. We are here to help!