I found this odd cable while cleaning out the garage of a house I recently bought. It's plugged in to a live outlet but doesn't appear to connect anywhere. It also has some wrapped junction in the middle. Super puzzling to me. Thanks!

Here is the whole length of the cord. It's in the garage of a house I recently purchased, built in 1982.

Here is the end of the cord, that I can't see connecting to anything.

3 Answers 3


That looks like heating tape.

You wrap it round water pipes in the garage or somewhere else cold. It provides just enough heat to stop the pipes freezing.

I've used this in the past on outside taps. It is available at most big DIY shops. It doesn't use much power.

  • 1
    Or possibly along rooflines to stop ice dams. The giveaway is that it's wrapped around or along a pipe. No AC power wire should ever be attached to the outside of a pipe (heat tape excepted, obviously) and no wire of any kind should ever be attached to electrical cable or conduit. Commented May 6, 2017 at 19:34
  • The consumption depends on the purpose of the heating tape. In the lab we are using such tapes to heat vacuum chambers so they are evacuated faster to high vacuum. In short ammount of time they reach 75 °C.
    – Crowley
    Commented May 7, 2017 at 0:17
  • 1
    This is correct, but note also that this isn't properly installed if it's pipe heat tape and should potentially be discarded if it has been operated in this condition. Heat tape doesn't pull a lot of power, and doesn't generate a substantial amount of heat when used as intended, but it is meant to be wrapped, in continuous pipe contact so that the heat it does generate can be evenly dissipated into the pipe and out of the cable itself (the line lump contains an ambient temperature thermostat). Operating it without contact with pipes could have deteriorated it if it's tape designed for pipes. Commented May 7, 2017 at 2:42

It's heat tape for that pipe in your garage.

You want to get some decent insulation back on the entire pipe, looks like the previous owner was trying different things to prevent freezing. Would be interesting to find what that pipe does, apparently it's in service now with the valves open.

  • I believe it's the main water line coming into the house
    – Chris
    Commented May 7, 2017 at 13:49

Heat tape! Only plug it in when it going be cold for long period of time. 32 and below.

  • 6
    You know, in some parts of the world “32” is beach weather.
    – JDługosz
    Commented May 8, 2017 at 7:52
  • yep especially here in Scotland! So long as it is sunny here it is barbecue and shorts weather!
    – GMasucci
    Commented May 8, 2017 at 9:46
  • 2
    @JDługosz Don't you mean "in most parts of the world"? :^)
    – Num Lock
    Commented May 8, 2017 at 10:47

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