Router Keeps Restarting by Itself

A router that restarts by itself is annoying precisely because it heals itself. The Wi-Fi vanishes for a minute or two, comes back, and there's nothing left to inspect. The good news: the cause is almost always one of five things, and the order to check them is fairly clear.

First confirm it really is a restart

When the Wi-Fi drops, look at the router. If all the lights go off and then come on one by one as when first plugged in, that's a restart. If the power and Wi-Fi lights stay on and only the internet light changes colour, the router is fine, the provider's connection dropped, and the guide for that is Wi-Fi connected but no internet. What each light means is in the guide to router indicator lights.

If you can't catch it in the act, open the router's admin page and look for uptime. A number that's always small, hours, not days, confirms the router is restarting repeatedly.

1. The power adapter (the most common cause)

An ageing adapter doesn't die outright; it produces unstable voltage. The router stays up under light load but restarts once many devices are active and its power draw rises. The tell: restarts happen at busy times, evenings when everyone's home, and rarely during the day.

Testing is cheap: borrow an adapter with the same voltage and current (printed on the router, e.g. 12V 1A) and use it for a few days. If the restarts stop, you've found it. Choosing a replacement is covered in faulty router power adapter and replacement.

2. Overheating

An overheating router protects itself by restarting. The tell: restarts are more frequent on hot afternoons, and the router's body feels hot, not warm, to the touch. Common causes are a closed cabinet, sitting on top of another warm device, or vents clogged with dust.

Move it into the open, clean the vents, and give it space from other devices. More in the guide to overheating routers.

3. Unstable mains power

A split-second flicker, one that doesn't even dim the lights, is enough to restart a router. The tell: restarts coincide with the air conditioner, water pump, or washing machine starting, or with other devices like the TV box restarting at the same time.

The fix is a small UPS or at least a voltage stabiliser. A UPS for a router doesn't need to be big; the cheapest one will ride through flickers and a ten-minute outage.

4. Buggy firmware

Some firmware versions leak memory: the router runs normally for a few days, runs out of memory, then restarts. The tell: the gap between restarts is almost always the same, say exactly every two or three days, unrelated to busy hours or weather.

Check for a firmware update, how to is in the guide to updating firmware. On a provider-supplied router, updates are usually pushed centrally; contact the provider if the version hasn't changed in a long time.

5. Too much load

Cheap routers have a limit on how many connections they can track. A home with 20–30 smart devices, several cameras, and torrent downloads can exceed it, and the router restarts when its connection table fills. The tell: restarts only during specific activity, such as downloading large files or when all cameras are recording.

Reduce the load, switch off unused devices, enable QoS, or consider replacing the router with a more capable one.

When you've tried everything

Factory reset and set it up from scratch, without restoring a saved settings backup. If after that, with a new adapter and in a cool spot, it still restarts, the hardware is faulty. Provider-owned routers can usually be swapped free via a fault report; for one you own, it's time to replace it.

Restarts at busy times → adapter. Restarts when hot → ventilation. Restarts alongside other appliances → UPS. Restarts at regular intervals → firmware. Restarts during specific activity → load. Check in that order, and most cases are solved at step one or two.

Frequently asked questions