How long do modems last?

Last Updated on August 13, 2018 by Dave Farquhar

If you feel like you replace your modem more often than you replace your computer, you’re probably not imagining things. And if your relative’s or neighbor’s modem lasts longer than yours, you may not be imagining things either. So how long do modems last? And what can you do about it?

If your ISP provides your modem, it’s not your problem when it fails. Except for the wait to replace it, I suppose. But you won’t be out any money. But if you have to provide the modem, the cost and life expectancy does matter.

How long do modems last?

how long do modems last?
How long do modems last? Cable and DSL modems typically seem to last 3-4 years, in my experience, due to power surges over the data line.

How long modems last varies. Back when I had DSL, I would get 3-4 years out of a modem before it started to malfunction or died outright. That seemed to be the consensus with other people I knew as well.

Cable modems seem to last about 3-4 years as well. But changing DOCSIS standards plays a role with cable modems. Sometimes a modem still works, but it doesn’t work with new standards. So a cable modem can go functionally obsolete while it still has some service life in it.

Modems for fiber-based services like AT&T U-Verse last longer. I got a good six years out of mine and we replaced it due to obsolescence, not breakage. What’s the difference? Fiber optics works on light, not electrical current. That all but eliminates power surges across the data line as a possible cause of death for that type of modem. Dirty power across the power line can still kill it. But in my experience with modems, going back to the 1980s, power surges across the data line are more common. It killed dialup modems back in the stone age of the 80s too.

Worse yet, a surge through your data line can potentially damage your router and network adapter as well.

How to make your modem last longer

A cheap surge protector like this one doesn’t do much to protect your modem. Look for a surge protector or UPS that has coax and/or RJ-11 connectors to protect your data line.

If your concerned about how long do modems last, the good news is that you can increase their life expectancy.

The first thing to do is to plug them into a surge protector, or better yet, a UPS. A surge protector gives the modem some protection against surges and spikes in electrical power. But a UPS is even better. A UPS acts like a cheap power conditioner, protecting you against dips in power (brownouts) and power failure as well. Dirty power decreases life expectancy. So a cheap UPS is a good way to increase a modem’s life expectancy.

But that only protects half your modem. To protect the more vulnerable part, get a surge protector or UPS with phone/coax protection. Surge protectors are rated in joules. The higher the rating, the bigger the hit they can protect your equipment from. A good surge protector has a light in it. When it’s worn out, replace it for continued protection.

Setting up your surge protector, UPS, or combination of the two

To protect your data line, unplug the connection from your ISP to your modem. Plug it into the appropriate connector on your surge protector or UPS. Then run a second cable from between your surge protector or UPS and your modem. This protects your data line, and should dramatically increase your modem’s life expectancy.

If you already own a UPS but don’t have a data port on it, you can get a surge protector with a data port and use it along with your UPS. The caveat when you use a surge protector and a UPS together is that how you connect them matters. Never plug a surge protector into a battery-backed port on a UPS. The UPS confuses the surge protector. Plug the surge protector into a non-battery-backed port if the UPS has one. Or better yet, plug the surge protector into the wall and plug the UPS into the surge protector. Then plug the power plug from your modem into the UPS and plug the data line into the surge protector.

Plug your router into the UPS as well. This keeps you connected during momentary power outages.

With your modem protected this way, your modem, router, and computer are all likely to last longer, saving you replacement costs. Hopefully this means you’ll be able to keep your modem running until it’s obsolete, not because it broke. And if your modem is obsolete, your router may be as well.

If you found this post informative or helpful, please share it!

One thought on “How long do modems last?

  • February 23, 2020 at 7:31 pm

    Thank you. I am going to give this a try. Ever since a lightening strike 6 months ago, I have gone thru 4 modem/routers….they all die within weeks…driving me crazy. Iam assuming it is the dirty power you are talking about. And since I have only dial up available in my area, it is a challenge to find dial up modem/routers for sale locally. Thank you for this advice.

Comments are closed.

%d bloggers like this: