Lightning and your modem…what to do?


The answer is quite simple. If there is any lightning whatsoever, unplug your modem / router immediately!

Turning it off is not good enough.

A nearby lightning strike can send a power surge through various materials: electrical wiring, copper phone lines, coax cable, plumbing pipes. In fact, all of these things actually “attract” the lightning!

So your modem/router is at a very big risk when this happens.

Your modem/router and computer are very sensitive pieces of kit, even brown outs and blackouts (in other words, power outages or electrical power surges) can zap them and other sensitive equipment when the power kicks in again.

How can I tell if my modem/router has been zapped?

It’s not always obvious as all it takes is for one tiny component inside to be fried. This is what to look out for…

  • Your internet connection will have dropped
  • The modem/router lights are going crazy even after a power cycle (or restart)
  • You can’t login to the modem/router to check the configuration
  • Smell a burnt plastic odour originating from your equipment
  • In many cases you may see the power outlet, plug, or the modem/router cables or main housing scorched

OK, so you are on NBN…does all this apply?


If you are on NBN Fibre to the Premises, then theoretically optical fibre does not conduct lightning strike power surges. But, the power source can! Your NBN box/NTD, or the utility box outside, or your router may have been zapped.

And if you are on NBN Fibre to the Node/Building, then from the node to your premises uses the copper line to which you have connected a modem/router.

You get the picture!

If it is not obvious that any equipment has been zapped and your internet has dropped out or is slow after a storm, then contact your ISP to check and trouble shoot your connection.

Will a Surge Protection Device (SPD) protect against a power surge?

Maybe…and it is certainly a good idea.

But like anything these days there are cheap SPDs and more expensive ones. Generally the more expensive ones are designed to protect more sensitive equipment such as your modem and computer from lightning and other surges – therefore investing more would be the better decision. The cheaper ones are really only designed for white goods – your washing machine and microwave for example.

You can’t predict when a storm is coming so SPDs definitely are a good investment.

Unfortunately, no surge protector is completely effective as some initial portion of the surge can sneak through, and a large surge could exceed the SPD’s capacity!

If you’re interested you can Google more info on how they work.

And the ultimate safe guard is…

If a storm is coming and you are at home, physically disconnect your modem, computer, printer, TV, and don’t forget your phone on charge from the mains socket to protect them all from a power surge.

A great alternative, if you really absolutely need to get online during the storm…

Grab your laptop (not on charge of course!), grab your mobile (also not plugged in) and connect to a hotspot from your phone while the storm passes. All wireless!

But an even better alternative, watch the spectacle! A free firework show at your doorstep.

Oh…and don’t forget to keep your computer backups up-to-date just in case it gets zapped!