What Is Surge Protection, and Do You Actually Need It?

Surge protection has gone from a rarely-mentioned extra to something offered on nearly every consumer unit upgrade quote, and understandably, people want to know whether it's a genuine necessity or an upsell.

Here's what it does, and how the current regulations actually treat it.

What a power surge actually is

A power surge is a brief, sudden spike in voltage above the normal supply level. It can come from a lightning strike near the property, switching events on the wider electricity grid, or even large appliances and motors switching off elsewhere in the building, which can send a brief spike back through shared wiring.

These spikes are usually far too brief to trip a breaker, but they can be more than enough to damage sensitive electronics — think TVs, boilers with electronic controls, and anything with a circuit board.

What a surge protection device does

A surge protection device (SPD) sits in the consumer unit and diverts excess voltage safely to earth before it can reach the circuits feeding your sockets and appliances. It's a single component fitted once, rather than something you'd need on every individual plug.

Is it actually required?

Current UK wiring regulations require an SPD risk assessment whenever a consumer unit is installed or upgraded, weighing factors like the consequences of a surge (data loss, safety systems, etc.) against the likelihood of one occurring. In many cases, particularly properties with a lot of connected electronics or in areas more exposed to lightning activity, that assessment concludes an SPD is genuinely warranted, not just a nice-to-have.

What it doesn't cover

An SPD protects against external and grid-related surges, not a direct lightning strike on the property itself, and it doesn't replace good practice like unplugging genuinely sensitive equipment during severe storms. It's one solid layer of protection, not a total guarantee.