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Five things can go wrong on a circuit. Your Ellon board may only notice three.
Overload, short circuit, earth fault, arc fault, surge. Those are the five, and no single protective device catches all of them. Which ones your board can actually see depends entirely on what is inside it, and most people have never been told. This page shows you the gap between what your board covers and what is available, so you can decide what is worth closing and what is not. From £550 + VAT.
The five ways a circuit fails.
Worth understanding before any quote, because every protective device is designed for one or two of these and blind to the rest.
Overload
Too much current drawn through a cable for too long. Nothing is broken. The cable simply heats up beyond what it was sized for, which over time degrades insulation and starts fires.
Short circuit
Live touches neutral directly. An enormous current flows for a fraction of a second. This is the dramatic one, and it is also the easiest to protect against.
Earth fault
Current escaping to earth, through damaged insulation, through water, or through a person. The current involved can be far too small to blow a fuse and still be more than enough to kill.
Arc fault
A loose or damaged connection sparking repeatedly. Current stays within normal limits, so overload and short circuit protection see nothing at all, while the arc quietly reaches temperatures that ignite surrounding material.
Transient overvoltage
A brief, very high voltage spike from a lightning strike on the network or a switching event. Milliseconds long, and long enough to destroy electronics throughout the house.
What your board actually covers.
Find the devices you have down the left, and read across. This is the single most useful thing on this page, and no other page covering Ellon has anything like it.
| What you have | Overload | Short circuit | Earth fault | Arc fault | Surge |
|---|---|---|---|---|---|
| Rewireable fuses | Yes | Yes | No | No | No |
| MCBs, no RCD | Yes | Yes | No | No | No |
| Split load, RCD on some circuits | Yes | Yes | Partly | No | No |
| Full RCBO | Yes | Yes | Yes | No | No |
| Full RCBO plus SPD | Yes | Yes | Yes | No | Yes |
| Add AFDDs | Yes | Yes | Yes | Yes | Yes |
Why "partly" is the important row
A split load board does protect against earth faults, but it shares one RCD across several circuits. So the protection is real, and the consequence of a fault is that everything behind that device goes off together. That is why it is worth changing, and it is a comfort argument rather than a safety one.
Why the arc fault column is mostly empty
Because it genuinely is. Arc faults sit inside normal current limits, which means the devices in almost every Ellon house cannot detect them. That is a real gap, honestly stated. Whether it is worth closing in your house is a different question, and the answer below is usually no.
Which gaps are worth closing, and which are not.
A gap existing is not the same as a gap being worth your money. Here is where we would and would not spend it.
No earth fault protection at all
Rewireable fuses, or breakers with no RCD anywhere. Your board cannot detect current leaking to earth through damaged insulation, through water, or through a person. This is the one genuine safety gap on the list, and it is the reason to replace a board.
Consumer unit upgrade, £550 to £950 + VAT
Shared RCD, and no surge protection
Individual RCBOs mean one fault takes out one circuit rather than half the house, which matters most if you have a freezer, home working or anyone who would struggle in the dark. Surge protection is cheap insurance for a house full of electronics, and the assessment is now based on the consequence of a surge rather than a calculation. You may decline it, and that gets recorded.
SPD £40 to £80 + VAT · RCBO £25 to £30 + VAT each
AFDDs in an ordinary Ellon house
Arc fault detection is required on socket circuits up to 32 A in higher risk buildings, HMOs, purpose built student accommodation and care homes. In an ordinary dwelling it is recommended, not required, and it adds meaningful cost per circuit.
If your home is a normal house or flat and somebody is quoting AFDDs throughout as a compliance requirement, that is not correct. We will fit them if you want the protection and understand what you are buying. We will not sell them to you as a rule that does not apply.
Where the standards actually sit in 2026.
The current version is BS 7671:2018+A4:2026, published on 15 April 2026. There is a six month transition, and from 15 October 2026 the previous version is withdrawn and A4 is the only current version. It is still the 18th Edition and there is no 19th. Note that BS 7671 is a standard rather than a law, so "withdrawn" is the accurate word rather than "illegal".
Amendment 4's headline changes cover stationary battery storage, functional earthing for ICT systems, Power over Ethernet and medical locations, so none of them forces a domestic board upgrade. It did touch the arc fault regulation, but only to re-point the trigger at higher risk buildings as defined by the Building Safety Act. For an ordinary house in Ellon the practical answer is unchanged. There is a fuller breakdown on our Peterhead consumer unit page.
On the Scottish framework: Part P does not apply here, and there is no Building Control notification and no competent person scheme, since those all belong to England and Wales. Ellon sits under the Building (Scotland) Regulations with Aberdeenshire Council as the Building Standards authority, not Aberdeen City. No building warrant is needed to replace a consumer unit in an existing house, but the work must comply with BS 7671 and be tested and certified.
If you let a property in Ellon, read this bit carefully
Two duties apply, and the second is the most overstated claim in the trade right now.
The first is a satisfactory EICR at least every five years by a competent person, with a copy to your tenants.
The second: since 1 March 2024 the Repairing Standard has required one or more RCDs rated at no more than 30 mA in the main consumer unit, normally covering the socket outlet circuit as a minimum, with the precise requirement depending on the installation. That arrived alongside new duties on lead pipes, fixed heating, safe kitchens and common doors.
What it does not say is that every circuit must be RCD protected, and it does not mean a working split load board now fails. A split load board has RCDs covering the socket circuits and will generally comply. What the duty genuinely catches is a let property with no RCD protection at all. If you have been told your compliant board has failed, ask which paragraph of the statutory guidance that comes from.
What it costs, and what happens on the day.
From £550 + VAT, guide to £950 + VAT depending on circuit count and complexity. All prices exclude VAT.
| Work | Price |
|---|---|
| Consumer unit upgrade, typical 100A domestic | from £550, guide to £950 + VAT |
| Consumer unit with EV charger bundle | £750 to £1,000 + VAT |
| Surge protection device, per device | £40 to £80 + VAT |
| RCBO, per device plus install | £25 to £30 + VAT |
| EICR, to establish condition first | from £150 + VAT |
| Earthing or bonding correction | quoted after survey |
On the day
We test the existing installation before anything is disconnected, because fitting a new board means taking responsibility for the circuits behind it. The board goes in, every circuit is reconnected, identified and labelled, and the main earthing and bonding are checked and corrected where needed. Then everything is tested through and you get an Electrical Installation Certificate with the full schedule of test results.
Power is off for most of a single day and we tell you the window in advance. If a fridge or freezer needs to stay alive, we arrange a temporary supply rather than leaving you to improvise.
Two things are quoted separately rather than absorbed: earthing and bonding corrections at the origin, which is the most common extra we find, and any existing circuit that fails its test during the change. A circuit that failed does not get quietly energised.
Ellon and Formartine.
Ellon itself, including the estates on both sides of the Ythan, and out through the surrounding Formartine towns and villages.
Testing on our Ellon EICR page, general work on our Ellon electrician page, car charging on our Ellon EV charger page. Also useful: consumer units across Aberdeen, what an EICR covers, when a rewire is the answer instead.
Ellon consumer unit questions.
Don't see yours? Call 07304 027013 or get in touch. We come back the same business day.
How do I tell what my board actually protects against?
Look at what the circuits sit behind. Ceramic holders with fuse wire, or breakers with nothing that has a test button, means no earth fault protection at all. Two banks each behind a device with a test button means shared RCD protection. Every circuit on its own device with its own test button means individual protection. Then read across the table above.
Do I need AFDDs?
In an ordinary house or flat, almost certainly not. Arc fault detection is required on socket circuits up to 32 A in higher risk buildings, HMOs, purpose built student accommodation and care homes, and only recommended elsewhere. Anyone quoting them as a compliance requirement for a normal Ellon home is mistaken. We will fit them if you want the protection, but not on a rule that does not apply to you.
Is my split load board illegal now?
No. A dual RCD split load board remains compliant. The argument for changing it is what happens when a fault occurs, since one fault takes out every circuit behind that RCD rather than just its own. That is a real inconvenience and sometimes a real safety issue if it kills the lighting, but it is not a legal failure.
Does Amendment 4 mean I need a new board?
No. Amendment 4 was published on 15 April 2026 and the previous version is withdrawn on 15 October 2026, but its main changes cover battery storage, ICT earthing, Power over Ethernet and medical locations. It did adjust which buildings trigger the arc fault requirement, but for an ordinary house the practical answer is unchanged.
I let a flat in Ellon. Do I need every circuit on an RCD?
No, and this is the most overstated claim going. Since 1 March 2024 the Repairing Standard requires one or more RCDs rated at no more than 30 mA in the main consumer unit, normally covering the socket outlet circuit as a minimum. It does not require every circuit to be protected, and a working split load board generally complies. What it does catch is a let property with no RCD protection at all.
Do I need surge protection?
It is no longer decided by a calculation. The assessment is based on the consequence of a surge, so for a house full of electronics, a home office or a heat pump it is usually worth the £40 to £80 + VAT. You can decline it and that decision gets recorded.
Do I need a building warrant, and does Part P apply?
No warrant is required to replace a consumer unit in an existing house. Part P does not apply in Scotland at all, and there is no Building Control notification or competent person scheme either. Ellon is under the Building (Scotland) Regulations with Aberdeenshire Council as the authority, not Aberdeen City. The work must comply with BS 7671 and be certified.
My board is plastic. Does that fail?
No. The requirement for non combustible enclosures applies to what is installed now, not retrospectively to a board already on your wall. A plastic enclosure on its own is not a defect.
Will a new board stop my circuits tripping?
It depends why they trip. If several circuits share one RCD and small leakages from normal appliances add up, individual RCBOs will fix it. If a circuit has genuinely degraded insulation, a new board will detect that fault more decisively, not less, and the circuit still needs repairing. Testing first tells you which you have.
How long does it take?
A straightforward change is a single day with the power off for most of it. You get the window in advance, and a temporary supply is arranged where a fridge or freezer needs to keep running.
Find out what your board misses.
Call Steven directly on 07304 027013, message us on WhatsApp, or use the form. The useful detail is what the circuits sit behind: fuse wire, breakers with no test button, two banks each with a test button, or every circuit on its own device. That one answer places you on the table above and tells us whether this is a real safety gap or a comfort upgrade. If it is the latter, we will say so. NICEIC approved, SELECT member, City and Guilds 2365-03 installation, 2391-52 inspection and testing, 2382-22 wiring regulations, £2M public liability insured.
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Faithful Spark Electricians Ltd · Consumer unit upgrades across Ellon & Formartine · NICEIC Approved Contractor · SELECT Member · City and Guilds 2391-52, 2382-22, 2365-03, 2921-34 · BS 7671:2018+A4:2026 · £2M public liability insured