Should you really trust the previous homeowner’s wiring?

Congratulations! You just moved into your new home. Well, it’s new to you. Rather than a new build, you chose for a home that someone else lived in. When you get there, you find a surprise: A lot of wiring’s already been done. There are a pair of wires running to the roof, plus a bunch of Ethernet cables run throughout the house. You’re thinking you scored bigtime… but did you?

Old coaxial cable isn’t always a good value.

If you’re planning to use satellite TV, you never want to reuse coaxial cable. At the very least it’s getting old and you don’t know the condition of the splices in the wall. When you see two lines — and only two — run up to the roof the best guess is that there was a satellite dish there but it was an older one. Newer ones either have one line down or four. The listing agent probably had the dish removed to make the home look nicer. For satellite, those lines should definitely be replaced.

However, you might find that you can put up a TV antenna or cellular booster and that the old cable could work just fine. TV antennas are a lot more forgiving of old cables. Over-the-air TV uses much lower frequencies than satellite so the cable doesn’t have to be the super-high quality level that you need for satellite TV.

For a signal booster, it’s sort of a 50/50 proposition. You can put the booster’s external antenna up and see if it works, but cell boosters use similar frequencies to satellite so they’re more sensitive to older or weaker cables.

Ethernet cables tend to have a pretty long life.

In most cases, ethernet cables that have been run through a wall tend to have a very long life, as long as they were installed right. You can get a very inexpensive cable tester that will help you trace and check the Ethernet in the wall. Generally though you’ll find it’s not a problem.

The only time I’ve seen issues with Ethernet in older homes is when there has been a pest problems. Silverfish like to eat the rubber sheaths of cables and this can create all sorts of problems. The problems show up first with relatively thin cables like Ethernet as opposed to thick electrical cables. If you have any reason to believe the home was unoccupied for a while, I would test all the cables. There may be a closet you can look at if the whole home was wired for Ethernet. If not, you may be able to look in the attic or crawl space.

If you need new cables…

You’ll find the best selection at We can make custom lengths for you or if you’d rather do it yourself, we have a massive selection of RG6 connectors, cables, and tools to choose from. If it’s network cables you’re looking for, you’d be hard pressed to find a better selection than we have. We also have grounding supplies, wall mounting and fishing supplies… everything to make sure that you don’t have to live with the previous homeowner’s mistakes.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 9,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.