- September 6, 2026
- By
- Blog
A consumer unit without RCD protection is not always an immediate emergency, but it should never be ignored. Are RCDs mandatory? The answer depends on the age of the installation, the work being carried out and how the property is used. For homeowners and landlords, understanding that difference can prevent unnecessary worry while making sure genuine safety issues are dealt with promptly.
An RCD is one of the most effective safety devices in a modern electrical installation. It is designed to disconnect the supply quickly if it detects electricity flowing where it should not – for example, through a damaged cable, faulty appliance or person receiving an electric shock. It does not replace sensible use of electrics, good wiring or circuit protection, but it adds a vital layer of protection.
Are RCDs mandatory in UK homes?
For new electrical work, RCD protection is required in most domestic situations under the current edition of BS 7671, commonly known as the Wiring Regulations. This generally includes socket circuits, circuits supplying equipment used outdoors and cables concealed in walls or partitions at a depth where they could be damaged by drilling or nailing.
That means a new socket circuit, a replacement consumer unit, garden power or many alterations to existing wiring will normally need 30mA RCD protection. A qualified electrician will assess the circuit, its location and the equipment connected before deciding precisely what is required.
However, the rules are not normally retrospective. In plain English, an older installation does not automatically become illegal simply because it was installed before modern RCD requirements were introduced. Many properties around Chester and the wider area still have older fuse boards or consumer units without RCDs on every circuit.
That said, “not automatically illegal” does not mean “as safe as a modern installation”. Older arrangements can provide less protection against electric shock, particularly where sockets, bathrooms, outdoor equipment or concealed cables are concerned. If the consumer unit is ageing, circuits trip regularly, or there are signs of damage or overheating, it is sensible to arrange an inspection rather than wait for a fault.
When an exception may apply
BS 7671 allows limited exceptions in certain circumstances, but these are not a shortcut around safety requirements. An exception must be based on a proper assessment and recorded by the electrician. For example, some specific equipment may need a different protective arrangement to avoid an unsafe loss of supply.
This is why electrical work should not be designed around a general rule found online. The right approach depends on the circuit, the property and the reason for the work. A competent electrician can explain the options in clear terms before anything is installed.
RCD rules when replacing a consumer unit
Replacing a consumer unit is a significant upgrade. Once a new board is fitted, the installation work must meet current requirements as far as the scope of the job allows. In most homes, this means RCD protection for the relevant circuits, often provided through RCBOs.
An RCBO combines overcurrent protection and RCD protection for an individual circuit. Unlike an older split-load board, where one fault might switch off several circuits protected by the same RCD, RCBOs can limit the disruption to the affected circuit. If a faulty washing machine causes a trip, for example, the lighting and other circuits may remain on.
There is a cost difference between basic RCD arrangements and a full RCBO consumer unit, so it is worth discussing the options. For many households, the reduced nuisance tripping and easier fault finding make RCBOs a practical long-term choice. The condition of the existing cables, earthing and bonding also needs checking before any upgrade is quoted.
Are RCDs mandatory for landlords?
Landlords in England must have the electrical installation in a rented property inspected and tested at the required intervals, normally at least every five years. They must provide tenants with the appropriate electrical safety report and act on observations within the stated timescale.
The law requires a safe installation and a satisfactory Electrical Installation Condition Report, or EICR. It does not say that every older rental property must have an RCD fitted to every circuit regardless of its condition. An electrician carrying out an EICR assesses the installation against safety standards, the risks present and the age of the wiring.
A lack of RCD protection may be recorded as an observation or recommendation, particularly where sockets could supply outdoor equipment or where there is increased risk of electric shock. The classification depends on the circumstances. It is not responsible to assume that every non-RCD circuit receives the same outcome without testing and inspection.
For landlords, the practical question is often broader than minimum compliance. An RCD or RCBO upgrade can improve tenant safety, reduce the chance of a serious incident and make future maintenance more straightforward. It may also be the most sensible solution where an EICR identifies concerns with an older consumer unit.
Bathrooms, gardens and external power
Some areas demand particular care. Electrical equipment in bathrooms, garden sockets, sheds, garages and outdoor lighting can be exposed to moisture, damage and heavier use. These are the places where effective RCD protection matters most.
Never rely on an old plug-in adaptor as a substitute for properly designed circuit protection. Plug-in RCDs can have a place as a temporary additional precaution, but they do not correct poor wiring, missing earthing or faults within the fixed installation. If an outdoor socket is damaged, trips repeatedly or has no suitable protection, stop using it and have it checked.
What an RCD does – and does not – protect against
RCDs are sometimes mistaken for a cure-all. They are not. An RCD may reduce the risk of a fatal electric shock by disconnecting quickly when it senses an imbalance in current, but it cannot make damaged electrics safe to use. It will not repair a loose connection, prevent every kind of fire, or guarantee protection if someone contacts two live conductors.
You still need correctly rated circuit breakers or fuses, sound earthing and bonding, suitable cable installation, and appliances in good condition. Burning smells, crackling sockets, scorch marks, electric shocks or frequent tripping should always be taken seriously. Switch off the affected circuit if it is safe to do so and arrange professional fault finding.
If an RCD trips once, it may have responded to a faulty appliance, moisture or a temporary issue. If it keeps tripping, do not repeatedly reset it in the hope it will stay on. Unplug appliances where safe, note which circuit is affected and get the cause investigated. Repeated tripping is the safety device doing its job, not a fault to bypass.
Testing RCD protection at home
Most RCDs and RCBOs have a small test button, often marked “T” or “Test”. Pressing it should switch the device off. Manufacturers commonly recommend testing this function regularly, often every three months, although you should follow the instructions supplied with your consumer unit.
Before testing, remember that the circuit will lose power. Save work on computers, avoid testing while cooking or using essential equipment, and reset the device afterwards. If it does not trip when tested, will not reset, or trips again immediately, arrange for an electrician to inspect it.
Testing the button only checks that the device operates mechanically. It does not prove the whole installation is safe, nor does it replace periodic inspection and testing. An EICR involves proper electrical tests and a visual assessment of the installation, including the consumer unit, circuits, accessories, earthing and bonding.
When to arrange an electrical inspection
An EICR is particularly worthwhile if you have just bought an older home, are planning alterations, have an ageing fuse board, or cannot remember when the electrics were last checked. Landlords should keep track of their existing report and arrange the next inspection before it expires.
For homeowners, an inspection gives you a clear picture rather than a guess. You may find that only targeted improvements are needed. Alternatively, the report may show that a consumer unit upgrade, remedial work or partial rewire is the safer and more cost-effective route.
At Gerrard’s Electrical Solutions, we explain findings plainly and quote for any recommended work before it begins. Whether you need an EICR, a consumer unit upgrade or help with a circuit that keeps tripping, the right next step is a proper assessment of your own installation – not assumptions based on its age alone.