Surge Protection Devices: Does Your London Home Need One?

If you have had a new consumer unit fitted recently, or had a quote for one, you may have seen a surge protection device, or SPD, on the list. Many London homeowners and landlords ask whether they really need one. This guide explains what an SPD does, when the wiring regulations expect one, and what it means on an EICR.

What a surge protection device does

An SPD sits in or next to the consumer unit and limits short, high voltage spikes on the supply. These spikes can come from lightning strikes on or near the network, or from switching on the grid and inside large buildings. Most are too brief to notice, but they can damage the electronics in TVs, routers, boilers, smart meters, chargers and alarm panels over time.

When the regulations expect one

The current edition of the wiring regulations, BS 7671, expects surge protection to be fitted on most new installations and when a consumer unit is replaced, unless a risk assessment shows it is not needed. In practice, almost every new consumer unit we fit in London now includes an SPD.

What an EICR says about SPDs

An EICR checks an existing installation against the current regulations, but older installations are not expected to have every newer feature. A missing SPD on its own is not usually recorded as a dangerous fault. Your electrician may note it as a recommendation, especially if the home has a lot of sensitive equipment or you plan to replace the board anyway. If your report shows other faults, our guide to what a C2 means on an EICR explains the codes.

Who benefits most

• Homes with home offices, servers, smart heating or alarm systems.
• Properties with EV chargers, solar panels or heat pumps.
• Blocks of flats and HMOs, where a single event can affect many tenants.
• Shops and small businesses with tills, fridges and IT equipment.

Adding an SPD to an existing board

Some consumer units have space and the right design to take an SPD. Older boards often do not, and fitting one may mean upgrading the board. Our guide on fuseboard replacement cost in London explains what changes the price.

Get advice

Energy North Ltd covers North, East and West London with City & Guilds certified electricians, and can usually attend within 48 hours. See our EICR service to have your installation checked.