Router keeps restarting or overheating?

Router maker TP-Link says a TP-Link router that keeps restarting is usually down to a power supply problem, overheating, outdated firmware (the router's built-in software) or the Auto Reboot setting being switched on. It also says auto-reboot problems are "really rare". Its advice is for its own routers, but the causes are worth ruling out on any hub. TP-Link tells you to try a different power outlet first, because a faulty outlet or unstable power supply is one of the most common causes of repeated reboots, and to work from the simplest fixes up. On that basis, we suggest this order:

1. Power: socket, extension lead and adapter.
2. Heat: where the hub sits and whether its vents can breathe.
3. Software: provider updates, and whether one went wrong.
4. Settings: a reboot schedule or a recent change.
5. The hub itself, which is your provider's to sort out if it supplied it.

It's worth the effort: TP-Link points out that repeated reboots drop every connected device and can knock smart home devices offline until they reconnect.

TP-Link says power surges or an unstable outlet can make a router restart repeatedly, even if the outlet seems to work normally. In practice:

• Plug straight into a wall socket for a few days instead of a crowded extension lead, and see if the restarts stop.
• Use the adapter that came with the hub. BT's Smart Hub 2 guide says to use only the adapter BT provides for that device and to contact BT for a replacement. When EE's hubs show a red light, its steps include checking you're using the correct power supply and, if you've recently got a new hub, the one sent with it. TP-Link says a replacement must match the output on the router's label, because a mismatched adapter can cause erratic behaviour.
• Check the cable at both ends. BT's advice when a hub shows no lights is to check the power cable is firmly in and connected to the mains.

Example: if the hub, a TV box and a speaker were all unplugged while you decorated, it's easy to put a lookalike adapter back on the wrong box. Compare the output printed on the adapter with the hub's label.

EE lists a flashing red light on its Smart Hub 7 Pro and 7 Plus as "Low power mode". It doesn't give the cause, but its red-light steps are these same checks: restart, power supply, overheating, then reset.

TP-Link calls overheating a common trigger for automatic reboots. Some providers make the link too: Virgin Media says a solid red light on the Hub 5 might mean a cable connection issue or that the hub is too hot. Its steps for that light:

1. Switch off at the wall.
2. Stand the hub upright in the open, vents uncovered, away from heat sources.
3. Check the cables are undamaged and pushed in firmly.
4. Leave it 15 minutes to cool, then switch on and allow 5 to 10 minutes to start.

If the light is still red and the hub isn't warm, Virgin Media's next step is a factory reset.

BT's Smart Hub 2 user guide is the most detailed provider advice we found, and most of the checklist below comes from it. It also says the hub is for indoor use only and shouldn't be used near flammable substances or in places such as a garage.

Providers update their hubs remotely, and some say an update briefly interrupts the connection:

• Sky updates hub and booster software automatically in the background, usually overnight. While it updates, the power light flashes and you can't use your broadband for a few minutes (Sky's light guide says an update usually takes about 15 minutes), and Sky asks you not to turn the hub off. Sky's light guide says a flashing amber power light means the hub is in recovery mode, which can happen after an update; if it has flashed for more than 15 minutes, Sky says to try resetting the hub.
• Virgin Media says a Hub 5 slowly flashing green is downloading a software update and will take a few minutes to reboot once the download finishes, and a Hub 3's internet light may flash green while it installs an update. A brand-new hub installs the latest software as it starts up, so leave it about 30 minutes.

Not every provider describes an interruption. BT says Wi-Fi Care, included with the Smart Hub 2 and 3, installs the latest updates without disrupting your service, and asks you to keep the hub switched on partly so it stays up to date. EE says WiFi Intelligence, included with all its broadband plans, applies automatic software updates to keep the hub secure.

BT's, Sky's and Virgin Media's terms all provide for these updates, and ISPreview, the UK broadband news site, notes late-night hours are when providers normally carry out maintenance and firmware updates.

So a few minutes offline in the small hours fits how Sky and Virgin Media describe updates. Restarts at random times of day don't fit that pattern, so keep working through power, heat and settings.

TP-Link says the Auto Reboot setting on its routers is sometimes on by default and can be mistaken for a hardware fault. If restarts happen at exactly the same time each day or week, look for a schedule in the router's settings; our guide to logging in to your router settings shows how. TP-Link also suggests reviewing anything that changed just before the trouble began (new devices, a new provider, configuration edits) and updating the firmware, which it says often fixes reboots caused by software bugs.

Providers say they update their own hubs automatically, so firmware is mainly something to check on a router you bought. That one is yours to look after: BT's terms, for example, say a non-BT router is the customer's responsibility. See using your own router.

After the power and heat checks, one proper restart is reasonable, using your provider's timings (our hub lights guide, linked above, lists them). Then leave it alone and watch, or you won't know whether it's still restarting by itself.

Resist restarting it over and over on a phone-line connection (ADSL, or FTTC where fibre runs to a street cabinet). BT says switching the hub off regularly can make the line appear unstable, which may lead to a reduced speed, and thinkbroadband says switching the router off and on a lot can lead Dynamic Line Management (DLM), the system that manages line stability, to slow the line.

A factory reset puts the hub back to how it arrived. TP-Link says it clears corrupted settings that may be causing instability, and Virgin Media says anything you changed, such as a new Wi-Fi password, must be set again. Note your Wi-Fi name and password and any settings you changed first.

A few days of notes give support something to act on:

• the date and time of each restart, and any pattern;
• the exact light colour and whether it flashes;
• where the hub sits, whether it felt warm, and which adapter and socket it uses;
• what you've tried, and anything that changed just before.

Then use your provider's test so the problem is on record. BT says that if you log in it will test your broadband connection, 24 hours a day, and can restart your router or book an engineer visit, and Virgin Media suggests testing your connection when the lights don't match its guide. Once things settle, our broadband speed test shows whether speeds have recovered.

No provider we checked sets a number of restarts that makes a hub faulty. Contact yours when:

• it still restarts after a different wall socket, the right adapter and a cool, open position;
• the restarts don't match a reboot schedule or an update;
• a fault light stays on after your provider's restart and reset steps;
• the hub is hot to the touch even in the open; or
• the hub or adapter shows damage (stop using it first).

For a hub your provider lent you, its terms set out what happens. Sky repairs or replaces faulty loaned equipment free unless you're responsible, for example through misuse, damage or tampering. Virgin Media says it can swap faulty kit at no extra cost. BT asks you to report faulty loaned kit and return it in pre-paid packaging, and replacements may be new or refurbished "as new". Vodafone's returns policy says it will replace a broadband hub found faulty within the first 30 days; after that it will try to repair it and tell you about any charges first, and it says the policy doesn't affect your statutory rights. Our guide to your rights when broadband equipment is faulty explains them, including for kit you bought. If the hub was knocked over or got wet, see lost or damaged broadband equipment. BT's Smart Hub 2 guide also says there's a slight chance an electrical storm could damage the hub, and recommends unplugging the power and phone line cable during one.

Questions to ask:

• Can you see the restarts or any errors on your side?
• Has my hub had a recent update, and is there a known problem?
• Will you send a replacement, and is there any charge?
• Do I return the old hub, and by when?
• If an engineer is needed, could the visit be chargeable? (See what happens on a fault engineer visit.)

Openreach says digital phone service usually works through a broadband router rather than a wall socket, and traditional lines are going digital by 31 January 2027. Vodafone says that because your phone connects to the router for Digital Voice, you can't use the landline if the router loses power until it comes back on, and BT says that if your broadband fails you can't make Digital Voice calls, including to 999. So a hub that keeps restarting can cut off the phone each time. GOV.UK says telecare devices (personal alarms that call for help) on a digital line may not work in a power cut, and Openreach says anyone who relies on the landline, has poor mobile signal or uses telecare should tell their provider, which can provide battery back-up support.

If someone at home depends on the phone or an alarm, report a restarting hub promptly and say so. See telecare alarms and digital landlines and digital landlines in a power cut.