Why does my circuit have continuity between neutral and earth when nothing is plugged in – Advice from Electriman, North London Electricians

Finding continuity between the neutral and earth terminals on a circuit can feel alarming, but in most UK homes it is completely expected and is built into how your electricity supply works. Here is what you need to know.

Why it is usually normal

In the vast majority of UK properties, the electricity supply arrives as what is called a TN-C-S or PME (Protective Multiple Earthing) system. Under this arrangement, the neutral and earth conductors are deliberately connected together at one point, which is the main earthing terminal inside your consumer unit or fuse board. Because of this bond, testing between neutral and earth anywhere in the installation will show a low resistance, usually well under 1 ohm. This is by design and is required to make the electrical safety system work properly.

When could it be a problem

Although a reading between neutral and earth is expected at the consumer unit, there are situations where it can point to a fault.

1. If the resistance is very high (several ohms or more) it could mean the neutral is only connected to earth through a fault rather than through the proper bonded path.

2. If you find a solid continuity reading at an individual socket that does not disappear when you remove the socket from the wall and isolate the wiring, there may be a wiring error where neutral and earth conductors have been swapped or have touched inside a back box.

3. If a circuit has been modified by a previous

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