Some warmth is expected from a router that has been on for a few hours. If it’s too hot to touch comfortably, something is wrong, and it’s worth tracking down the cause before the hardware fails.
An overheating router left running can wear down its internal parts until it stops working altogether. Airflow is usually the first thing to fix. If that doesn’t solve it, you’ll need to work through the likely causes in turn.
Warm is normal, hot isn’t
Every router connected to a wall socket produces some heat. Inside a home Wi-Fi router are processors, memory, wireless radios and power management modules, and each of them gets warm as it runs.
More and more new routers are built around a system on a chip (SoC) design. One example is Broadcom’s BCM6765 SoC, which places the core networking components on one semiconductor chip.
Speed is another factor. Modern routers can push thousands of megabits of data every second, which loads up the CPU and generates more heat. Once a router exceeds its recommended operating temperature, connections may drop or the device may shut itself off.
The symptoms that point to heat
You can feel the first warning sign yourself: the router is uncomfortably hot when you touch it. Overheating often brings dropped connections and sluggish network performance, though those two problems alone don’t prove the router is failing.
The picture changes when heat shows up alongside other faults, such as network speeds that swing up and down, or freezes and shutdowns that happen at random. If that’s what you’re seeing, the CPU is probably throttling itself to lower its internal temperature and protect its components.
The Wi-Fi bands may also switch, and the router’s effective range can shrink. Switching it off to cool and then turning it back on may restore performance for a time, but only until it overheats again.
Start with where the router sits
Three causes account for most overheating: poor ventilation, a faulty power adapter or a router that is failing. Diagnosing the cause and fixing it happen in the same steps, so begin with the cheapest option.
When ventilation is to blame, relocating the router to an open spot with good airflow can fix it. Avoid tucking it inside a closed cabinet or stacking items around it, because either one blocks the air.
Keep it clear of windows where direct sunlight can reach it. It should also sit away from computers and game consoles, which give off a lot of heat when they’re working hard.
Clean the vents and update the firmware
Most home routers have vents to let air through, and those vents can fill up with dust and debris. Cleaning them on a regular basis keeps the air flowing and the temperature lower.
Keep the firmware up to date too. Updates frequently fix stability and performance problems, which can sometimes resolve bugs that cause unusual heat.
Check the power adapter next
If the temperature stays high after cleaning and a firmware update, turn to the power adapter. An adapter that is faulty, or that isn’t rated for your router, could deliver more current than the router’s components can cope with. That leads to extra heat and can damage the components.
An adapter rated for your particular router should supply power correctly and help keep the heat down. Confirm the rating before buying a replacement.
When the router itself is the problem
If improved ventilation, a firmware update and a new power adapter still leave the router overheating, the device itself is the most likely culprit. It may be close to the end of its life, and at that stage the answer is to replace it with a new router.