Heat Tape & Roof Heat Cables: What to Check Each Fall

Winter guide

Two systems, one job

A lot of homes and cabins in Summit and Wasatch counties rely on electric heating cable to get through winter. There are two common kinds, and people often call both of them "heat tape":

Roof and gutter de-icing cable. Usually run in a zigzag along the lower edge of the roof, through the gutters and down the inside of the downspouts. Its job is to keep a path open so meltwater can drain instead of freezing into ice dams and icicles.
Pipe heat tape or heat cable. Wrapped or run along water pipes in crawl spaces, unheated garages, well houses and under cabins, to keep the water inside from freezing.

Both sit idle all summer, then get asked to work on the coldest nights of the year. Snow sliding off a roof, ladders, critters, sun and years of heating and cooling all wear them down. And the worst time to discover a dead cable is during a January cold snap at a cabin you're not at. A fall check, done in October or early November while the roof edge is clear and the crawl space is easy to get into, catches most problems.

Safety first

Unplug a cable before handling it, moving it or cleaning around it.
Look, don't fix, when it comes to wiring. If a cable, plug or outlet is damaged, unplug it and leave the repair to an electrician.
Do roof-edge checks from a ladder on dry, clear days. Don't walk a steep, icy or metal roof to look at a cable.
Never wrap, staple, nail or tape over a heat cable unless the manufacturer's instructions allow it.

Roof and gutter cables: what to check

Clips and the zigzag pattern

Roof cable is held in its pattern by clips or holders attached to the shingles, the roof edge or the gutter. Snow sliding off the roof in spring often pops clips loose or drags loops of cable down into the gutter or off the edge entirely. From a ladder, look for loops that sag below the roof edge, sections lying loose on the shingles, and clips that are broken or missing. A cable that has slid out of position can leave gaps where ice dams build up. Re-seating cable in existing clips and replacing broken clips with the right type for your roof is routine handyman work.

The run through the gutter and downspout

De-icing only works if there's a heated path all the way to the ground. The cable should run along the bottom of the gutter and down inside each downspout to the outlet. If the cable stops at the top of the downspout, meltwater can drain into a cold, unheated downspout and freeze solid there. Check that the cable reaches the bottom, and that the downspout outlet and any extension are clear so water can leave. A downspout that empties onto a shaded walkway will still ice up the walkway, so moving or extending it can matter as much as the cable.

Debris around the cable

Leaves, pine needles and shingle grit packed around a cable in the gutter hold moisture, keep heat from doing its job and can damage the cable's outer jacket over time. Gutters with heat cable need to be cleaned by hand, gently, without scraping tools that can nick the cable. This is a big part of why we recommend a fall gutter cleaning before the cables go on for the season.

Visible damage

Look along the cable for cracked, flattened or cut jacket, exposed wire, kinks, spots that look melted or scorched, and places where the cable is crushed under a gutter guard, a ladder hook or ice. Any of those means unplug it and call an electrician or the company that installed the system. Don't tape a damaged heat cable.

Controls and thermostats

Some systems have a plug-in thermostat or a controller with a temperature and moisture sensor that turns the cable on only when it's needed. Check that it's still connected, the sensor isn't buried in leaves and any indicator light comes on. Systems with a wall switch or controller wired into the house belong to an electrician if they stop working.

Pipe heat tape: what to check

Pipe heat tape is usually tucked in crawl spaces and under cabins, where nobody looks until a pipe freezes. Once a year, with a flashlight, check:

That it's plugged in. It sounds obvious, but cords get bumped by storage bins or unplugged to free up an outlet over the summer.
The indicator light or built-in thermostat. Many heat tapes have a small light on the plug or a thermostat that clips against the pipe. The thermostat needs to touch the pipe, not hang in the air.
How it's installed. Some heat tapes must never overlap or cross over themselves, while some self-regulating cables can. Look for the label or the manufacturer's instructions. Tape that's wrapped over itself, buried under the wrong kind of insulation or run on a pipe material it isn't rated for is a problem.
Signs of age and heat. Brittle, cracked, discolored or blackened spots, melted pipe insulation and a burned smell are all reasons to unplug it and have it replaced.
Coverage. Pipes nearest the outside walls, the crawl space vents and the water service entry are usually the coldest. Note any exposed section without heat tape or insulation, and ask a plumber or electrician whether it needs it.

Foam pipe sleeves on easy-to-reach pipes and sealing drafts near pipes help a lot, and those are handyman jobs. Replacing heat tape on pipes is usually a job for a plumber or electrician. Our frozen pipes guide covers the rest of the freeze protection plan.

Power: the GFCI test

Heat cables should be plugged directly into a ground-fault protected outlet (GFCI) or a circuit with built-in ground-fault protection. That protection is what shuts the power off if water gets into a damaged cable. Test it every fall:

With the cable plugged in, press the TEST button on the GFCI outlet. It should click, and the outlet should lose power. If the cable has an indicator light, it should go out.
Press RESET. Power and the indicator light should come back.
If the GFCI won't trip, won't reset or trips again as soon as the cable is plugged in, unplug the cable and call an electrician. A GFCI that trips every time can mean water in a damaged cable or a fault in the outlet.
Outdoor outlets should have an in-use cover that closes over the plug, so snow and meltwater can't get in.
No extension cords, no power strips, and no cords pinched in windows or doors. An outlet that feels warm, looks discolored or smells hot needs an electrician.

Handyman or electrician?

What a handyman can check and do

Visual inspection of roof, gutter and pipe cables for damage, sagging and position
Re-seating cable in existing clips and replacing broken clips
Cleaning gutters and downspouts by hand around the cable, and clearing downspout outlets
Making sure the cable runs through the gutter and down the downspout
Confirming cables are plugged directly into a GFCI outlet, and testing that the GFCI trips and resets
Checking pipe heat tape for visible damage, overlaps and thermostat contact, and adding foam sleeves to reachable pipes
Extending downspouts so meltwater drains away from walkways
Sending photos and notes to owners who aren't in town

What needs an electrician

New circuits or new outlets for heat cable, including adding a GFCI where there isn't one
Hardwired systems, controllers and wall switches
Damaged cable, cords, plugs or outlets, and any scorched or melted spots
A GFCI or breaker that keeps tripping
Installing new roof de-icing systems (often with a roofer) or replacing heat tape

Heat cable doesn't fix the cause

Roof heat cable keeps a drain path open, but it doesn't stop ice dams from forming. Ice dams come from heat escaping into the roof, and the long-term fix is attic air sealing, insulation and ventilation. Our ice dam guide explains why. For vacant cabins and second homes, pair your heat cable check with the rest of the list in our cabin winterizing guide and the fall home and cabin checklist, and consider a Wi-Fi temperature sensor that alerts you if the heat or power goes out. We can check your cables as part of snow-season prep or gutter cleaning.

While you are marking things before the snow, see our guide to snow stakes, plow damage and spring yard repairs.

Holiday lights and heat cables should never share clips or outlets. See our guide to hanging holiday lights without damaging gutters, shingles or heat cables.

When to call a pro

Electrician: new circuits or outlets, hardwired heat cable systems and controllers, damaged cables, plugs or outlets, and GFCIs or breakers that keep tripping
Roofer or de-icing installer: new roof heat cable systems, snow guards and roof repairs
Plumber: frozen or split pipes, replacing heat tape on pipes and full drain-downs
Us: visual cable checks, clips, gutter and downspout cleaning around cables, GFCI test-and-reset checks, foam pipe sleeves and photos for owners who are away

Where we help

Call or text (435) 321-2591 Message us on Instagram

Heat cable FAQ

How do I know if my roof heat cable is working?

Plug it in on a cool day and check that any indicator light comes on, then carefully feel a section near the plug after several minutes to see if it's warm. Also confirm the GFCI outlet trips and resets. If it doesn't warm up or the GFCI keeps tripping, unplug it and call an electrician.

When should I turn on my roof heat cables?

Before the first real snow, usually in November in Summit and Wasatch counties. Systems with a thermostat or controller turn on automatically. Manual systems are typically left on during snowy weather and turned off in spring. Follow the manufacturer's instructions.

Can I plug heat tape into an extension cord?

No. Heat cables should plug directly into a GFCI-protected outlet. If there's no outlet close enough, an electrician can add one.

Can you clean gutters that have heat cable in them?

Yes. We clean by hand around the cable, re-seat it in its clips if it's loose and tell you about any damage. Repairs to the cable itself go to an electrician.

Can you check my heat cables while I'm away from my cabin?

Yes, for outdoor cables we can reach and pipe heat tape in accessible crawl spaces. We test the GFCI, look for damage and send photos. Call or text (435) 321-2591, or message @kamasvalleyhandyman on Instagram.

We focus on general handyman work and are not a licensed electrical, plumbing or general contracting company. For jobs that need a licensed trade, we'll tell you upfront and point you in the right direction.

Heat tape and roof heat cables: fall checks