Surge protection devices clamp brief overvoltage events, typically caused by switching on the network or by nearby lightning activity. In a house full of electronics, boilers with control boards and heat pumps, the value proposition is easier to see than it was twenty years ago.
What it protects
Anything with sensitive electronics: home working equipment, media systems, appliance control boards and modern heating controls. It works at the board, so it covers the installation rather than one socket.
What it does not do
It is not a substitute for RCD or overcurrent protection, and it does not protect against a direct strike. It also has a finite life — a status indicator shows when the module needs replacing, which is a thing worth checking at each inspection.
When we suggest it
During a consumer unit change, when the incremental cost and labour is small; in properties with significant equipment value; and where a household has already lost equipment to a supply event. Where the board is staying as-is, retrofitting is possible but the economics are less obvious.
Common questions
- Does an SPD need its own space in the board?
- Yes, it occupies board ways, which is a consideration on a full unit.
- Do plug-in surge strips do the same job?
- They protect what is plugged into them only, and generally to a lower standard.
- How long does an SPD last?
- It depends on how many events it absorbs. The indicator window tells you when it has expired.
- Is it required?
- Its use is risk-assessed rather than universally mandatory in dwellings; we will explain the reasoning for your property.
Ask us to price an SPD as a line item on your board quote so you can see the actual difference.
Related guides
- What Affects the Cost of a Consumer Unit UpgradeTwo identical-looking boards can be very different jobs once the cover comes off.
- Arc Fault Detection Devices (AFDDs) at HomeAFDDs target a failure mode that other protective devices genuinely do not see.
- Electrics for Working From HomeMost home offices were bedrooms, and bedrooms were wired for a lamp and an alarm clock.