Is it normal for a router to feel hot and hot to the touch? What degree is considered over-priced? I used a thermometer for three days, and the cooldown was just a trick

Every summer, someone in the backend asks me: The router feels like a hand warmer—is it about to catch fire? I used to panic too. That old machine at home was so hot in summer that I didn't dare put anything on top, and even put a wet towel over it to cool down. Looking back now, that was just a disaster. This time, I borrowed a thermometer and measured each of the three machines at home for three days, settling the temperature issue clearly.

be clear first: a router is just a small radiator

routers don't consume much power; most home machines range from 5 to 15 watts. I tested each metering socket one by one, and AX3000T 5 watts when empty, about 8 watts when fully loaded. But this little bit of power has almost no mechanical loss, and basically turns into thermal , and it runs 365 days a year without shutting down, so heat is continuously accumulated.

the warmth to the touch is part of the design; if it doesn't heat up, that's abnormal. My criteria for judgment are simple: if you can keep your hand without discomfort, that's normal; If you want to pull back after three seconds, you need to check the . If it's so hot you can't even touch it, don't hesitate—keep reading.

there's another uncommon point: heat generation is not directly related to signal strength or internet speed. My K3 with firmware flashed and running at full load didn't increase at all, but the temperature did climb from 52°C to 68°C. The extra heat was all from the CPU and amplifier chip working overtime, not boosting the speed.

want to know exactly how much alcohol consumption is, there are three options

method one: directly check backend. here, we need to pour cold water on this: most brands' backend doesn't even show you the temperature. ASUS's web backend doesn't even have this option when searching the menu, but it leaves a hidden page—after logging into the backend, you add a 'ajax_coretmp.asp' after the address bar, press Enter to show the CPU temperature, and the original firmware works without needing to enable SSH. Xiaomi's 31.1 also doesn't have a temperature page in the background. If you want to see it, you need to unlock SSH first and then use the command to check. I've previously written about the unlocking process the about enabling SSH on Xiaomi routers. Machines flashed with OpenWrt are the easiest to deal with. In SSH, enter a single command: cat /sys/class/thermal/thermal_zone0/temp, and divide the number by 1000 to get degrees Celsius.

method two: temperature measuring gun. an infrared thermometer that costs about thirty yuan is a universal method. Aim it at the hottest part of the device's casing (usually in the middle of the top, directly above the SoC) and it will read. All my data for the past three days was measured by it, and it's much more reliable than the feel.

Method Three: Rough Judgment on the Back of the Hand. a simple remedy when you don't have tools: you can keep it on the back of your hand and keep it there, and the shell should be within about 45 degrees; It can hold out for about three seconds, around 55 degrees; Touch it and you reflexively pull your hand back, moving beyond 60 degrees. The margin of error is significant, but enough to judge whether to take action.

temperature ranger: decide whether to use it based on your seat

Having numbers alone is useless; you need a ruler. Chip manufacturers generally set the junction temperature limit at 90 to 110 degrees, but that's the baseline for 'not burning'—not for 'comfort.' Based on my own tests and the caliber I translated, I have compiled this table:

my three-day test was just right at the top of the range. The same AX3000T is placed on the living room table, with a 41-degree shell; Put it into a low-voltage box, 52 degrees; The most extreme time was when I casually stacked it on top of a set-top box. At 56°C—the set-top box had 15 watts on standby, which was a big heat generator. Stacking two together was basically heating each other. This comparison illustrates one thing: same machine, different environments can make a difference of 15 degrees, and starting first is more effective than switching machines.

the high heat: chips can withstand it, capacitors can't

This is the part I most want to make clear. Many people think that higher temperatures at most shorten their lifespan, and that it's vague. I reviewed quite a bit of information from capacitor manufacturers, and this account actually counts quite well.

router, the real heat concern isn't the SoC chip—the chip's junction temperature limit is above 90°C, and 70°C is the daily heavy load for it. What truly shortens the circuit is the electrolytic capacitor on the circuit board, especially the few in the power supply section. Inside the electrolytic capacitor is the electrolyte; the higher the temperature, the faster it volatilizes. There's an old industry rule called the 'Argenius Law': for every 10-degree increase in temperature, the capacitor's lifespan is cut in half; For every 10-degree drop, it doubles .

to calculate specifically: a capacitor rated at 105 degrees for 2,000 hours operating at 65 degrees Celsius has a theoretical lifespan of 2,000 times 2 to the fourth power, about 32,000 hours, which equals a little over three and a half years; Similarly, if this capacitor is soaked in a 75-degree environment for a long time, its lifespan will be cut in half to one and a half years. In other words, the same router, whether cooling is good or poor, the difference is not just a few degrees of reading, but twice the lifespan . My old TP that had lasted 8 years and opened it up. Both capacitors bulged. The problem wasn't with the chip, but with the capacitors—I mentioned this in the article about how many years router can last.

besides shortening lifespan, high fever also has immediate symptoms: disconnections at night, 5G bands inexplicably slowing down, and restarts more frequently. My Xiaomi unit was once overheated in summer until it ran dry, forcing me to do a cooling upgrade. Details like fan alignment and vertical ventilation are all in that , so I won't repeat them here. Additionally, I set a weekly scheduled restart schedule. In hot weather, the machine can catch its breath. the timed restart setup path different brands have different names, so just refer to that one.

three cooling tips, sorted by the amount spent

first axe, move the position, 0 yuan. weak current cabinets are a major disaster area—tin boxes are stuffy and can't get air. In summer, my cabinet measured 45 degrees Celsius inside, and soaking the machine in it was like a sauna. I deliberately moved the router to a low, ventilated area it. Besides removing the box, there are two other actions: don't stack it on set-top boxes or optical modems—the lesson I learned from the 5-degree test is right there; When the machine is placed upright or elevated, the cooling area is larger than when lying flat, and the signal is not at a disadvantage. The way to position it is tested five times before moving .

the second axe, put it up, 10 yuan. buy two router stands or a whole silicone pad, elevate the bottom of the machine by two centimeters so air can pass from underneath. I tested that this can lower the temperature by 3 to 5 degrees, which is like spending little to achieve great things. Silicone mats have another benefit: the machine doesn't press directly on the table, and the desk doesn't leave any prints.

third axe, upper fan, 20 to 40 yuan. USB small fan blowing is the most aggressive move; heavy-load machines can push the temperature back to around 10 degrees, but the trade-off is dust and a bit of noise. My suggestion is to use the first two axes first, and only apply the fan if it can't be suppressed. By the way, for a few ASUS models with built-in fans (like the RT-AX89X), just use the default automatic fan speed. Don't turn it off manually—turn off the fan under heavy load, and the overheat protection triggers and immediately throttles the speed, which actually drops the speed.

three types of 'fake fever'—cooling down doesn't solve the problem

if the cooling still gets abnormally hot after tinkering, it's very likely not the cooling fault. Check all three directions one by one.

First, the power adapter is aging. router's power supply becomes weak after prolonged use; a rated 12V might only be down to 9V, and the machine repeatedly restarts at the edge of low voltage, showing signs of "overheating and frequent disconnections." My old AC2100 was rebooted overnight, and flashing and resetting didn't help. The multimeter only had 9V left after a single power supply, and changing the power supply fixed it. how to match the voltage and current of a power adapter ? Check Xiaomi's article, it's universal.

second, a firmware bug causing the CPU to run idle. some firmware versions have defects; even when there's no traffic, the CPU runs at full speed, and the machine heats up abnormally. the correct way to upgrade firmware written before, remember to copy your broadband account before upgrading.

third, the equipment is really overloaded. dozens of smart devices at home, the CPU running under high load for a long time, and the lack of heat is a normal physical outcome. after I made slimming for 62 machines, the machines were noticeably less hot—the load was reduced, and the heat naturally came down. In this case, switching to a higher-spec machine is fundamentally better than any cooling upgrade.

Finish with a general order: first measure with the thermometer, then close to the splitter at 45 degrees; If it exceeds the limit, move the weak current box to exit and leave the heat source; Re-pad brackets; Still can't hold the upper fan; After all the tests, it's still hot. Check the power supply, upgrade the firmware, and the devices, and only then is it time to change the machine. Don't think about changing phones just because it's hot—eight out of ten times you can just move your phone to a new location.