Heat tape on water pipes, used safely

Electric heat tapes and pipe heating cables keep exposed water pipes from freezing. They're usually in crawl spaces and under mobile homes, beach houses, cabins and other homes where pipes can freeze. Many stay plugged in all year and switch on through a thermostat when the outdoor temperature nears freezing.

In the mid-1990s, faulty heat tapes caused an estimated 1,500 home fires, 10 deaths and 100 injuries a year. In the six years of data before 1990, over half of heat tape fires involved mobile homes and trailers. Many people don't inspect theirs regularly, and some don't know their home has one at all.

What you need

• A flashlight
• The heat tape's installation instructions, if you have them
• The number of a qualified electrician

Steps

1. 1

   Find out what you have

   Look along any exposed water pipes you can see from inside the house, such as in an unfinished basement, a garage or a utility room. Note where each heat tape is plugged in. A tape in a crawl space or under a mobile home is the electrician's to check, not yours.

   10 min

2. 2

   Look at what you can see

   Where a tape is in plain view, look for discoloration, especially at the plug, and for charring, cuts or breaks in its covering, or bare wires. If you see any of them, unplug it and have it replaced.

   5 min

3. 3

   Check the outlet

   The three-prong plug belongs in a three-prong outlet, so the tape is grounded, and that outlet should be protected by a ground-fault circuit interrupter (GFCI).

   2 min

4. 4

   Book the inspection

   Some people have the know-how to inspect heat tapes themselves, but most should have a qualified electrician do it. Book the inspection every fall, before winter.

   5 min

5. 5

   Ask about how it's installed

   During the visit, ask the electrician to confirm the installation follows the maker's instructions. The tape should sit directly on the pipe, not on top of pipe insulation. It shouldn't overlap itself unless the maker allows it. Its end cap should be sealed and off the ground, so moisture can't get in.

   5 min

6. 6

   Keep insulation off it unless the maker says otherwise

   Don't cover heat tape with insulation unless the maker advises it. If it's insulated, the insulation should be a non-flammable kind such as fiberglass, never foam or vinyl, and never more than the maker recommends. Too much insulation can start a fire.

   2 min

Using it for the right job

Heat tape made for water pipes isn't for gutters, driveways or fuel lines. If a tape has a thermostat, its instructions say whether the thermostat goes against the pipe under the insulation or stays exposed. Whenever a different type or brand of tape goes in, read its instructions fresh.

For other ways to keep pipes from freezing, see Preventing frozen pipes, and the first hour if one bursts.