A fuse box, fuse board, or consumer unit is an array of electrical fuses controlling all the electrical circuits in your property. However, times change, technology improves, and regulations require consumer units containing electronic circuit breakers to replace physical fuses. That doesn’t mean you must immediately change your old fuse box. But, as you upgrade old domestic electrical systems, you must install modern consumer units. But how much does this new technology cost?
In the UK, the average cost of replacing a fuse box for a modern consumer unit is £100-£400 plus £120-£320 for an Electrical Installation Condition (EIC) Report. These amounts vary depending on the number of circuits involved and whether the inspection finds issues.
This guide describes when to upgrade consumer units and what regulations to follow. We also discuss how much an upgrade costs, the factors that affect the price, and the types of consumer units available.
How Much Do Fuse Box Replacements Cost?*
The cost of changing your consumer unit from fuses to circuit breakers varies with the type suitable for your property because of the number of variables. The table shows typical prices, including labour but excluding VAT.
|Task||Price Range||Average Costs|
|To Replace Existing Fuse Box with New Consumer Unit||£100-£150||£125|
|To Replace Circuit Breaker||£50-£60||£55|
|To Buy Populated Consumer Unit||£50-£250||£100|
*The data in this guide are average and estimated figures correct at the time of writing (September 2022). They can vary due to several factors that a professional Part P domestic electrician must consider. Therefore, use the form on this page to get accurate quotes from professional electricians tailored to your unique circumstances.
11 Fuse Box Replacement Price Factors
Several factors affect the cost of replacing a fuse box for a modern consumer unit.
1. Size of House
Larger houses have more circuits or rings than smaller houses. Therefore, expect to use a 15-way RCD dual split load consumer unit in a large house, which usually costs more.
2. Current rating
Consumer units can also vary in price depending on the device’s current rating (amp rating).
|Current rating||Price Range||Average Price|
|40A Unit – 2-3 ways||£270-£330||£300|
|63A Unit – 1-6 ways||£330-£370||£350|
|80A Unit- 7-10 ways||£400-£440||£420|
|100A Unit – 7-16 ways||£470-£530||£500|
3. Type of consumer unit
All consumer units operate differently, and several are available to suit your requirements. These are the most popular:
- Domestic Switch Fuse.
- Full Loaded Consumer Unit.
- Garage Consumer Unit.
- High Integrity Consumer Unit.
- Dual RCD Consumer Unit.
- Populated Consumer Unit.
- Split Load Consumer Unit.
- Unpopulated Consumer Unit.
We discuss the properties of each of these later in this guide.
4. Electrical inspection
Before installing a new consumer unit, your electrician should inspect the wiring in your home for various electrical issues. Then, based on the inspection results, you will receive an EIC report. If there are any problems, you must have them rectified before installing the new consumer unit. Don’t panic, you may have something as simple to fix as a faulty light switch or electrical socket. However, it might be an issue that requires complete rewiring. Never avoid rewiring your home if the EIC report needs it, as the most common cause of electrical fires is faulty or old wiring. Typically, an electrical inspection and report cost £120-£320.
5. New sockets and lighting
It might be the right time to add more sockets and lighting if you have a new consumer unit. Your electrician can give an estimate for this. Expect an hourly rate to be around £45/hr, plus the cost of materials.
If your EIC inspection shows up old or faulty light switches or wall sockets, replace them with new ones. Generally, switches and sockets cost around £30-£60 for labour to install and from £3-£10 to buy, depending on their specifications. If you select high-quality, high-tech light switches, a dimmer costs from £5-£100, while a smart dimmer costs £150-£220.
6. Gas and water pipes bonding?
If your home is relatively new or you’ve had new plumbing fitted recently, your gas and water pipes will already have bonding. This means that the metal pipes and fittings have been electrically connected to the earth connection in the consumer unit, thus preventing residual current from travelling along metalwork in case of an electrical earthing fault. Electrical bonding is compulsory under the building regulations. But, if you have new pipework installed, it will already be included in the price. Otherwise, retrofitting to old pipework will cost more and is usually charged hourly.
7. Condition of the original wiring
Generally, domestic wiring has a life expectancy of 50 to 70 years. However, this can be shorter depending on previous modifications, damage to the insulated sheathing, and the quality of installation. Usually, new houses have professionally installed new wiring, but old houses will probably have issues that require fixing to comply with Part P of the building regulations. The EIC inspection will highlight wiring issues, and replacing wiring will add to the basic quotation. Furthermore, the electrician must also look at the ceiling pendant light fittings. They must all be fire-rated, while bathroom ceiling lights must have a high IP Rating (Ingress Protection Rating).
8. Wire relocating
Wiring must sometimes be extended or moved to a better location when replacing a fusebox, especially when renovating. Relocating a consumer unit will cost extra, between £200-£500, depending on its location.
9. House rewiring
The EIC inspection might show that part or all of your domestic wiring needs replacing, an operation known as rewiring. The cost to rewire your home depends on its size, type, and wiring length.
Small one-bedroom flats typically cost £2,000-£2,500 to rewire. In comparison, a two-bedroom terraced house costs £2,000 to £3,500. In contrast, a three-bedroom semi-detached house costs £3,000-£4,500, and a four-bedroom detached property costs about £6,000.
Labour rates in London and Southeast England are 15%-20% higher than in other places in the country, so your quotation will vary accordingly.
Sometimes if the electrician has to travel out of a specific radius, you can expect to pay extra for his travelling time.
11. Call-out fee
Many electricians charge a call-out fee to ensure they aren’t out of pocket by accepting a minor job. Typically, expect to pay around half to one day’s labour as a call-out fee. But, this will be the maximum you pay if the job takes less than this time.
What’s entailed in the job?
Unless you are a qualified Part-P electrician, a contractor registered with a competent person scheme who can self-certify their work as complying with the building regulations, you should leave electrical installation alone. However, it’s often helpful for the customer to understand what’s involved when replacing a fusebox.
Initial EIC Inspection
- Carry out an EIC inspection of the existing circuits.
- Complete an EIC report.
- Fix any issues found by the inspection.
Changing your consumer unit
- Disconnect the mains electricity supply, so there’s no danger when replacing the consumer unit.
- Lift the lid from the fusebox.
- Remove each fuse in turn.
- Disconnect the wires from the fusebox.
- Remove the fusebox from the wall and set it aside for safe disposal according to local waste disposal regulations.
- Take the new consumer unit and remove the front panel.
- Fix the consumer unit back box to the wall.
- Reconnect the wires to the correct outlets.
- Insert the different rated circuit breakers into the appropriate slots.
- Securely reattach the front panel.
Testing the installation.
- Using a voltmeter perform an initial test on the installation.
- Perform additional circuit tests on each ring main.
- Record results on an Electrical Installation Certificate.
- The electrician gives one copy of the Certificate to the homeowner.
- Within a few days, a registered electrical organisation logs the work with the local council’s Building Control department.
- The householder receives a letter to confirm the council has been informed and the installation conforms to the UK building regulations.
Types of Consumer Units
The first thing we must do is understand what a consumer unit consists of and how they work. This article from Consumer Unit World describes a consumer unit.
The Main Switch
This unit isolates the consumer unit from the electricity meter. Before starting any work on your electrical system, turn this switch off.
An RCD or Residual Current Device monitors all the circuits in your property. Its purpose is to prevent electric shocks and identify faults that could become more serious such as an electrical fire. If there is a fault, the switch notices that the electrical flow isn’t balanced and immediately trips the power. The Wiring Regulations 2008 specify that all new or rewired properties must contain an RCD for safety purposes.
You can read more about how an RCD works here.
The MCB or Miniature Circuit Breaker is the modern alternative to the fuse that protected circuits in old-type fuse boxes. You can buy them in a range of standard current ratings from 6A to 50A for domestic consumer units. The MCBs trip when either of two different faults occurs.
- A power overload. Perhaps too many appliances are plugged into the same circuit.
- Overcurrent. An overcurrent forms when a circuit has a defect, such as a loose live wire.
You can read more about MCBs here.
The RCBO, or Residual Current Breaker with Overcurrent, combines an RCD and MCB. Therefore, it protects the circuits against electric shocks, overloads and overcurrent.
You can read more about an RCBO here.
An SPD or Surge Protection Device isn’t always necessary in a consumer unit. However, during the initial consumer unit installation, an electrician will perform a risk assessment to determine if your system will benefit from an SPD. It protects the electrical system and all connected appliances and equipment.
You can read more about Surge Protection here.
There are several types of consumer units. Here are some of the most popular.
Domestic Switch Fuse.
A Domestic Switch Fuse is a consumer unit with only one circuit. Typically, the circuit connects sub-mains and circuit extensions. Usually, you can buy one of these for £30-£90.
Full Loaded Consumer Unit.
A Full Loaded Consumer Unit (FLCU) comes with a full set of MCBs and two RCDs. The complete unit has a maximum of 10 to 15 usable circuits and costs £60-£125. However, an FLCU doesn’t give accurate circuit control, so electricians often choose other units.
Garage Consumer Unit.
A Garage Consumer Unit is very compact and usually protects the electrical circuits in garages and other outside buildings such as sheds, workshops, and house extensions. Typically, these units offer 2 to 5 usable circuits and cost £20 to £60.
High Integrity Consumer Unit.
A High Integrity Consumer Unit (HICU) has three neutral bars, RCBOs, and two MCBs. Therefore, they offer complete circuit separation and protection for critical and standard electrical circuits. So, for example, a fault in your lighting won’t affect essential circuits such as security, fire alarms, and domestic freezers. Even though a HICU is useful, it’s one of the most affordable consumer units, costing £40 to £150.
You can read more about a High Integrity Consumer Unit here.
Dual RCD Consumer Unit.
A Dual RCD Consumer Unit has two RCDs and a conventional main switch. This unit is very popular among electricians as it’s one of the most affordable and useful available. For example, one RCD can protect the upstairs circuits while the second can protect the downstairs. Typically, this unit costs £35-£130.
Populated Consumer Unit
A Populated Consumer Unit comes already fitted with a main switch, two RCDs, all necessary MCBs and an isolator switch. Therefore, the electrician needs no additional parts, which saves money. Typically a Populated Consumer Unit costs £30 to £240.
Split Load Consumer Unit
A Split Load Consumer Unit contains a main switch and an RCD, in addition to the usual MCBs and RCBOs. Typically, to buy a Split Load Consumer Unit, you need to pay £50 to £130.
Unpopulated Consumer Unit
An Unpopulated Consumer Unit comes without any circuit protection, thus allowing the electrician freedom to design the consumer unit’s configuration to suit the property. Typically, expect these to cost from £30 to £120.
Signs Your Fuse Box Needs Replacing
A qualified Part-P electrician will do an EIC Inspection to determine the condition of your electrical circuits. However, it’s useful for the property owner to know what to look out for so they can call in the electrician in the first place.
- Look at your existing consumer unit to see if it has a wooden back. If so, you must replace it.
- If your fusebox trips regularly, there is a fault somewhere in the system, and you should contact an electrician immediately.
- Do the lights or other electrical installations flicker or dim? If so, this could be a sign you need upgrading. Contact an electrician for an inspection.
- Do you smell a faint burning odour at light switches or wall sockets? If so, there might be a fault with the wiring. When upgrading the wiring, you must also upgrade the consumer unit.
One more thing. If your electrical system hasn’t had any work done on it for more than 50 years, expect some significant upgrades for safety and efficiency. Call an electrician for an inspection.
What To Ask Your Electrician
To ensure you hire a qualified electrician, ask a few simple questions.
- Is the electrician registered on a competent person scheme as a Part-P electrician? Certified electricians belong to the government-approved competent person scheme or are members of the ECA or NICEIC who also have an approved contractor’s register.
- Does the electrician belong to an association? The leading electrician’s trade associations are:
- What’s the hourly or daily rate? Expect charges of £40-£80/hr or around £250/day.
- How long will the installation take? If the inspection shows nothing to be done, replacing the fusebox should take around 4 or 5 hours.
- How long will the initial inspection cost? Typically, an inspection takes from 2 to 4 hours.
You might think of other questions. But, these few simple ones will ensure the electrician does an excellent job at a reasonable price.
Benefits of Replacing Your Fuse Box
There are several reasons why you should replace your fusebox. Here are the most important.
Installing a new consumer unit decreases the chance of an electrical fire caused by faulty wiring and fittings. The unit’s devices have built-in safety components that automatically disconnect the power supply before the current damages you or your property.
A new consumer unit with circuit breakers allows you to protect and isolate different electrical installation sectors. Therefore, a fault in one sector won’t affect the operation of the others. For example, faulty lighting won’t affect the electric shower or freezer circuit.
It’s unlikely that an old fuse box contained RCDs that continually monitor the flow of electricity within your property. Not only do they safeguard your indoor appliances, but they also protect electricals outdoors too. For example, if you accidentally cut your electric lawn mower cable, the RCD will immediately trip, cutting off the power to the device. This guarantees that you won’t suffer electrocution.
UK Regulations & Safety Standards
Usually, you won’t need to know most of these as the qualified Part-P electrician you hire knows everything there is to know about the laws relating to domestic electrical work. However, all the information you need is in Part-P of the UK Building Regulations. In summary, Part-P (or Approved Document P) includes detailed information on the required procedures and who is allowed to carry them out. Anyone carrying out electrical work must be competent, know about and understand how electrical fittings operate and have the necessary knowledge to check electrical safety circuits.
Part-P also contains information on electrical safety and what might happen if there is an electrical fault. Furthermore, it also includes information on the design, installation and inspection of electrical systems and the testing of work after completing the job.
Other Approved Documents within the Building Regulations interact with electrical installations. These include:
- Part A (Structure) – For the depth of chases and size of holes in walls and joists.
- Part B (Fire Safety) – General fire safety of electrical systems, fire alarm and detection systems, fire resistance when cables penetrate floors, walls and ceilings.
- Part C (Site preparation and resistance to contaminants and moisture) – How electrical cables penetrate structures without allowing rainwater and radon gas ingress.
- Part E (Resistance to the passage of sound) – How to soundproof cable penetrations.
- Part L (Conservation of fuel and power) – Using energy-efficient lighting.
- Part M (Access to and use of buildings) – Height from the power sockets and light switches to the floor surface.
Before fitting a new consumer unit, the electrician must conduct an Electrical Installation Condition Inspection and complete a report to ensure the property’s electrical system is safe and operates correctly. Generally, there is no need to change anything if all components work correctly. However, most electricians usually advise their customer to upgrade the consumer unit when renovating the property.
Installing an RCD is compulsory when upgrading electrical installations. However, they can be sensitive and trip for no apparent reason. Electricians often solve this by splitting the circuits into an upstairs and downstairs ring. But, this will also cost extra money.
Can I replace a fuse box myself?
The answer to this is a simple “NO”. Replacing an old-style fuse board with a new consumer unit containing circuit breakers is complicated and extremely dangerous. It is also a legal requirement to complete an Electrical Condition Installation Report before making any significant electrical changes. And only someone who belongs to one of the government-approved electrical organisations can do this. Therefore, leave it to the professionals.
Fuse Box vs Consumer Unit: Difference?
Let’s consider what the terms “Fuse Box” and “Consumer Unit” mean, as some people use them interchangeably. First, the fuse box and a modern consumer unit do the same job, but a consumer unit has several improvements and does the job better.
A fuse box was the only significant safety cut-out device used in a domestic electrical system. They contained fuses which contained specific standard thicknesses of wire. The electrical current for each circuit flowed through the wires during everyday use. But, whenever the system experienced an electrical problem, the wires melted (or fused). Unfortunately, it usually took two or three seconds for the wire to melt and break the electrical connection, so there was an increased chance of electrical fires to property and fatal electric shocks to people.
Modern consumer units contain electronic devices called circuit beakers instead of wire fuses. These devices continually monitor the electrical power in the circuits and trip, cutting the power if they detect faults, malfunctions or imbalances in the circuits.
One significant advantage to the householder is that following a trip, the circuit breaker only needs resetting rather than replacing a fuse wire.
If you have an old-style fuse box, it’s sensible to hire a qualified electrician to replace it for a modern consumer unit with RCDs and other circuit breakers. These devices instantly cut the power in your circuits, which is safer and provides peace of mind that your home is unlikely to experience electrical fires or fatal electric shocks.
Complete the form on this page, and you’ll receive up to four fuse box replacement quotes from qualified Part-P electricians near your home.