The ultimate guide to the consumer unit in your house

consumer unit

Getting a consumer unit replaced is a common problem that I face when being contacted by my customers about the electical works in their houses.

I decided to write this guide to show the rules and regulations about consumer units, as well as the question that everyone asks… What is right for my home?

This will help you make an informed decision to when it comes to choosing the right electrician to carry out the work in your home.

consumer unit

What is a consumer unit?

Simply put, a consumer unit is a device that allows all the electrical items in your house to connect to the main electricity supply. They are also known as Fuse boards, Distribution Boards and have lots of other names too, but essentially they are a means to safely send electricity to where its needed and individually isolate and protect the circuits.

Older consumer units such as the one pictured below typically use fusewire and various types of fuses for protection of the circuits. This has been replaced by modern devices that are safer, easier to use and more reliable.

What do you really need to know?

Before heading down the rabbit hole of regulations, safety, and the various Do’s and Don’t around Consumers units, here are the main things you need to know.

  • If you have fuses then its probably time for an upgrade.

Its important to note that this is not a law or a direct regulation, it s is however a huge step forwards in safety and limiting the risk of an electric shock in the event of a fault.

  • According to Fire Investigators, an extremely high percentage of house fires were due to burnt out connections caused by poor workmanship and lack or proper maintenance of fuse boards.

This fact led to a regulation change brought into place in January 2016. This does not mean that all old consumer units are unsafe, but it does drive home the point that you should have regular checks carried out on your electrical installation.

  • Since 2005 if you have a fuse board upgrade or a new circuit wired to your consumer unit, under Part P of the building regulations your local authority must be notified.

By law, the homeowner or landlord must be able to prove that all electrical installation work on their property meets the requirements of Part P, or they will be committing a criminal offence. A registered Electrician can do this for you.

With these 3 main points covered lets get into the details.

How to use a Consumer Unit

A consumer unit (old or new) is fairly simple to use with only a few serviceable parts. There are some key ares that it is worth highlighting to make you aware of what you should do in the event of circuit tripping out or a blown fuse.


When do I need to Upgrade my Consumer Unit?

Where you run into problems is that older installations (and consumer units) tend to become damaged with time, wear and tear and general use. They also become outdated by new regulations, so when having further works carried out, the electrician would be required to leave his work up to the current standards. This means that new kitchen you have been thinking about could require upgrades to add new circuits, RCD protection, Gas and water Earth Bonding upgrade and a new consumer unit. Extra space is also an issue. 20 years ago, we had different power requirements. In 2018 and going forwards it is usual to have 10+ circuits in a small house.

Common modern requirements could be:

  1. Shower
  2. Oven
  3. Hob
  4. Garage
  5. Central Heating
  6. Sockets Upstairs
  7. Sockets Downstairs
  8. Kitchen Sockets
  9. Lights Upstairs
  10. Lights Down Stairs
  11. Smoke Detectors
  12. Immersion Heater

The regulations say a new consumer unit needs to have space left for future upgrades, and we haven’t got the fun things like Hot Tubs and Solar Installation yet. As you can see, it is very common for a fuse board upgrade to be required due to modernisation of a property.


There are lots of abbreviations and technical jargon when it comes to Electrical Installations.

Luckily, the things that it is important for you to know is quite limited.

  1. Can you see a main earth and bonding conductors?
  2. Does your consumer unit have Switches?
  3. Do you have trip buttons?
  4. Are all your socket circuits covered by the trip devices?

If you can answer yes to these 4 questions then chances are that you are mostly upto date, or close enough to

Thats about it really. Whats important to realise, is that if the installation is installed correctly, and is in a good condition then no matter how old it is, it can still be deemed ‘safe’


Consumer units and earthing go hand in hand. The first thing I would look for when checking an electrical installation is the earthing set-up. This is something that requires an Electrician to do correctly, but a visual inspection will give you a good idea if there are any immediate concerns.

Take a look at and around your electric meter and try and find you main earthing conductor. This will usually go into a connection where you main electricity supply enters the property. You should also check your Gas meter and Water Stop tap for an earth bonding cable.

Part P and Consumer Units.

As I talked about at the start of his article, Part P of the Building Regulations require electrical work in a dwelling (or house) to be notifiable to a local building control body if it includes certain types of work including,

installation of a replacement consumer unit (fuse box)
installation of one or more new circuits
rewire of all circuits
partial rewire
new full electrical installation (new build)
Circuit alteration or addition in a special location (Certain areas of a bathroom)

An electrician registered with one of the approved schemes (NICEIC, NAPIT, STROMA) will carry out this notification as part of the job. It is a criminal offence to carry out notifiable electrical works and not inform the relevant body.


If you have any questions about your consumer unit or would click a free electrical safety check please contact Ben on 07909833076 or fill in our contact form