Short answer
Look at four things: is there an RCD in the consumer unit, are there screw-in fuses instead of breakers, do sockets have earth contacts, and is the wiring cloth or PVC. If the RCD is missing or there is cloth-covered wiring, the installation is decades old and it needs an inspection and usually renewal.
Who this article is for Anyone who lives in an older home or is buying one. You can look yourself; I do the measuring and assessing.
The four features that tell you most
1. No RCD. Compulsory in new builds since 1975, and introduced more widely for socket circuits after that. If there is not a single RCD in the consumer unit, the core of the installation is more than half a century old. This is the most important point: the RCD is what makes touching a faulty appliance survivable.
2. Screw-in fuses. The porcelain cartridges with a coloured indicator. They work, but they cannot be tested, and there is always one that was once replaced with a heavier one than the cable can handle.
3. Sockets without earth contacts. Two holes without the metal strips on the side. In a kitchen or bathroom that is a reason to act quickly. In a living room with only a lamp it is less urgent, but it no longer belongs.
4. Cloth-covered wiring. Cores with a sleeve of woven fabric with rubber underneath. After sixty years that rubber has hardened and breaks when touched. If you come across a junction box in such an installation, the insulation sometimes literally falls off.
What else gives away how old it is
- conduit with wires drawn in: good news, because then renewal without chasing out walls is often possible
- lead sheath around the cable: from before the war, really needs replacing
- push-in terminals without a spring in the junction boxes: notorious for getting hot
- two circuits for the whole house: normal in the sixties, now far below standard
- an earth wire on the water pipe: allowed in the past, no longer allowed now, and no longer works since water pipes are plastic
What it means
An old installation is not automatically dangerous. But the margins are gone: there is no RCD to catch a fault, no earth to carry current away, and material that is at the end of its life.
This does not have to happen in one go; the order does matter.
What you want in any case:
- an RCD on the socket circuits
- sound earthing, measured and not assumed
- earthed sockets in the kitchen, bathroom, outdoors and in the loft
- circuits suited to what is on them nowadays
That can be done in stages. A complete renewal does not have to happen in one go, as long as the order is right.
Starting with measurement
Before anything is replaced, I test the installation: insulation resistance per circuit, earth electrode resistance, the operation of the RCD and the continuity of the earth. From that follows what really needs doing and what can wait.
That report is also what you need when buying a home or for the insurance. What replacing a consumer unit involves is in consumer unit replacement.
From my own work
In a home from 1954 in Sittard I still found the original cloth-covered wiring in conduit, with insulation that crumbled as soon as the cores were touched. The meter cupboard had two screw-in fuses and no RCD. The residents had lived there for forty years without problems, and that is exactly the misunderstanding: nothing happens until one day it does.
When to call an electrician
- There is no RCD in the meter cupboard
- You see cloth-covered or crumbling wiring
- There are sockets without earth contacts in the kitchen or bathroom
- You are buying a home from before 1980 and want to know where you stand
An inspection with a test report gives clarity and is the basis for a plan in stages. Request a quote or call +31 43 204 18 26.
Frequently asked questions
Is an installation without an RCD immediately dangerous?
Not immediately, but the margin is gone: there is nothing to catch a fault before you feel it. That is the first thing I tackle.
Does everything have to be renewed in one go?
No, it can be done in stages, as long as the order is right: first the RCD and the earthing, then earthed sockets in the places that matter.
Do I need such a test report when selling?
It is not compulsory, but it gives a buyer certainty and saves discussion. It is also useful for an insurance claim after damage.
Further reading
Is my meter cupboard still safe? 10 things you can see yourself
Ten things you can see yourself without unscrewing anything. If you recognise three or more, it is time for a chat.
Type A, type B or type F RCD: which do you need
Type A is the standard. Type B only where DC leakage can occur, and that is less often than sellers say. Saves hundreds of euros.
Testing your RCD: do this twice a year
Thirty seconds' work, twice a year. And the honest story about what that test button does and above all does not prove.
Questions and comments
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