Best Heat Tape and Heat Cable for Freeze-Prone Pipes (2026)

Some pipes freeze no matter what you do: the supply line in a vented crawl space, the run along an unheated garage wall, the pipe to a well house. For those, heat tape (makers call it heat cable) is the fix: a cable taped along the pipe that keeps the water from freezing. It is also a product the CPSC has warned about since at least 1990. In 1996 the agency estimated that faulty heat tapes caused about 1,500 fires, 10 deaths, and 100 injuries a year, and it singled out tapes that are old, worn, or improperly installed and maintained.

This guide covers when heat tape is the right answer, the difference between self-regulating and constant-wattage cable, how to size it, what can go over it, the safety rules, and three plug-in cables from Raychem, Frost King, and EasyHeat. If a pipe is frozen right now, start with our frozen pipes guide instead.

Try These Before Heat Tape

Heat cable is for a pipe that still freezes after the basics. The American Red Cross starts with insulation in attics, basements, and crawl spaces, and sleeves on exposed pipes. Seal gaps where pipes pass through exterior walls. Keep the heat no lower than 55°F when you're away, and let faucets on exposed runs drip during hard freezes. Drain outdoor faucets before the first freeze (our outdoor faucet guide shows how), and work through the freeze-protection list in our winter home maintenance guide. If a pipe still freezes after all that, add heat cable. The Red Cross lists UL-listed heat tape or heat cable as an option for exposed water pipes.

Already have heat tape? A house you just bought may have it on some pipes. The CPSC found that many homeowners never inspected their heat tapes, and some didn't know one had been installed. Check the crawl space, the garage, and any supply line in an unheated space. Inspect any tape you find before winter, and replace one with no testing-lab listing or of unknown age.

Self-Regulating vs. Constant-Wattage Cable

Constant-wattage cable

Constant-wattage cable puts out the same heat per foot along its whole length whenever it is on: 7 watts per foot for the Frost King and EasyHeat kits below. Nothing turns a hot section down, so any spot where the cable touches itself runs hotter. EasyHeat warns that overlapped contact points can exceed ignition temperatures. These cables run straight along the pipe and are never spiraled, crossed, or overlapped. A built-in thermostat turns them on when the pipe drops below about 38°F and off at about 45°F.

Self-regulating cable

Self-regulating cable adjusts its output at each point to the temperature there. Raychem's FrostGuard puts out about 6 watts per foot on a 40°F pipe and less as the pipe warms, and Raychem says it can't overheat even when overlapped or closely spaced, so you can spiral it or wrap extra around a valve. The trade-off: FrostGuard has no thermostat, so it's energized whenever it's plugged in.

What that means for plastic pipe

PEX, PVC, and other plastic pipe need a cable its maker rates for that pipe. Raychem rates FrostGuard for metal and plastic water pipes, with a separate length chart for plastic, and EasyHeat rates the AHB for water-filled plastic supply pipe, including PEX. Frost King is narrower: its FAQ limits plastic to Schedule 40 supply pipe from 3/8 to 1-1/2 inches, says its kits aren't made for PVC, and rules out flexible lines such as mobile home feed lines, so for PEX or PVC choose FrostGuard or the AHB. The constant-wattage makers add conditions: the pipe must stay full of water, and Frost King and EasyHeat both recommend wrapping plastic pipe in aluminum foil first so the heat spreads evenly. None of them goes on a garden hose or flexible vinyl tubing.

What Actually Matters When Choosing

Rated for your pipe

Match the cable to the pipe's material, diameter, and contents. FrostGuard covers metal or plastic water pipes up to 2-1/2 inches; the Frost King and EasyHeat kits cover water-filled supply pipes up to 1-1/2 inches. The CPSC says never to use heat tape designed for water pipes on gutters, driveways, or fuel lines. The 120-volt FrostGuard is the exception here: Raychem rates it for roof-and-gutter de-icing too.

Length sized to the run, valves included

The CPSC says to measure the pipe's diameter and length, then buy the cable its manufacturer recommends for that size. For FrostGuard, Raychem says to add 1 foot per valve or spigot and to spiral any extra cable evenly along the pipe. Constant-wattage cable is different: never cut it or spiral it to use up extra length. Frost King says never to use a cable longer than the pipe; EasyHeat lets the non-thermostat end double back up to 3 feet along the opposite side of the pipe, never touching or crossing itself. For runs between standard lengths, Frost King's chart allows a slightly shorter cable on small pipe, or two cables on opposite sides of larger pipe. Neither kit goes on a pipe shorter than 3 feet.

The thermostat, and where it goes

Frost King says to tape the thermostat tight against the pipe at its coldest end and insulate over it. Placement varies by model, so the CPSC says to check whether yours goes against the pipe under the insulation or hangs uncovered.

Plug-in vs. hardwired

All three picks are plug-in kits with a lighted, grounded three-prong plug, and the CPSC says to always use a three-prong outlet so the tape is grounded. Hardwired kits, such as Raychem's 240-volt FrostGuard, whose cord is meant to be connected in a junction box, need an electrician. Raychem and Frost King both say never to install heat cable in walls, floors, or ceilings.

The outlet: GFCI, and kept dry

The CPSC says to plug heat tape into an outlet protected by a ground-fault circuit interrupter (GFCI). Raychem requires ground-fault protection because arcing from a damaged cable may not trip an ordinary breaker, and EasyHeat says the AHB must be GFCI protected. Frost King strongly recommends it. EasyHeat notes that the heat tape outlet in a manufactured home built before 2014 wasn't GFCI protected when built; if you're not sure about yours, have an electrician add a GFCI outlet or use a portable GFCI cord. Raychem also requires an outlet protected from rain, and the CPSC says to keep the end cap sealed and off the ground. If a GFCI keeps tripping, the cable may be damaged: unplug it and inspect it rather than moving it to an unprotected outlet. Our breaker guide covers resetting a GFCI safely.

Insulation over the cable: follow the maker exactly

The CPSC's rules: put heat tape directly on the pipe, never over existing insulation. Don't cover it with insulation unless the manufacturer says to. If you do, use non-flammable insulation such as fiberglass, not foam or vinyl that could catch fire from a failing tape. Never use more insulation than the maker recommends; over-insulation can cause a fire.

The makers' limits differ. The constant-wattage kits set a maximum of 1/2 inch of non-flammable insulation: fiberglass or equivalent for Frost King, fiberglass (with a vapor seal) or non-flammable foam for EasyHeat. Raychem sets a minimum for FrostGuard: at least 1/2 inch of fire-resistant, waterproof insulation such as preformed foam or fiberglass, or 1 inch where temperatures reach -20°F. The simplest choice that satisfies the CPSC and all three makers in most climates is half-inch fiberglass pipe wrap with a vapor seal or waterproof outer wrap (1 inch over FrostGuard where temperatures reach -20°F). Don't put ordinary foam sleeves meant for bare pipe over heat cable.

Heat Tape Safety

These rules come from the CPSC and the makers' instructions, and none of them bend.

• Buy only listed cable. The CPSC urges replacing uncertified heat tapes more than three years old with tapes certified to UL, CSA, or FM standards, which have a much better safety record. All three picks carry a UL or CSA mark.
• Use it only on pipes it's rated for. Never on hoses, flexible tubing, or fuel lines, or on pipes hotter than the rating (150°F for FrostGuard, 155°F for Frost King). Reread the instructions when you switch brands; the CPSC notes the requirements often differ.
• Use GFCI protection every time, as the CPSC says, even where a maker only recommends it.
• Skip extension cords unless the maker allows one. Raychem prohibits them. Frost King allows one only if necessary: a properly sized, grounded, UL- or CSA-certified cord suitable for outdoor use. Better: have an electrician add a GFCI outlet within reach.
• Inspect every season. The CPSC says every fall; Frost King says at the start of the season and monthly while in use, including for animal chewing. Mobile homes and trailers accounted for more than half of the heat tape fires in the CPSC's data, and it says most people should have a qualified electrician inspect.
• Replace, don't repair. Raychem says never to repair or energize a damaged cable, and Frost King says its cable has no serviceable parts.
• Install before the deep cold (minimum 15°F for Frost King and EasyHeat, 5°F for FrostGuard), and never plug in a cable while it is still coiled.
• Keep combustibles away. EasyHeat says no combustible material, including cellulose insulation, paper, or wood, within 1 inch of the pipe; follow your own cable's clearance rule. Keep working smoke alarms on every level; see our smoke alarm guide.
• Add a backup alert. A leak sensor with a freeze alert beside the protected pipe warns you if the cable, its thermostat, or its GFCI quits.

At a Glance

Picks Worth Buying

1. Best overall — self-regulating and forgiving

FrostGuard is the hardest cable here to install wrong, since extra wraps around a valve won't create a hot spot. The 120-volt kit comes in lengths from 6 to 100 feet, each with a 6-foot cord and a lighted, grounded plug; the link is the 6-foot kit, so buy the length Raychem's chart gives for your pipe. Raychem requires a ground-fault protected outlet and waterproof, fire-resistant insulation, prohibits extension cords, and says to fasten the cable with fiberglass tape or nylon ties, not vinyl electrical tape or duct tape. The Raychem brand now belongs to Chemelex, so newer packaging may not say nVent. Pros: tolerates overlap, suits plastic pipe, widest pipe range here, CSA certified, installs down to 5°F. Cons: no thermostat, so it draws power whenever it's plugged in, even on mild days; costs more than the constant-wattage kits; insulation over it is required. Best for: plastic pipe, runs with valves and fittings, and anyone who wants the most forgiving install.

2. Best budget — a thermostat kit for short runs

Frost King's kit is the classic hardware-store heat cable, with a built-in thermostat that turns it on below 38°F and off at about 45°F and a plug with a power light. Kits run from 3 to 30 feet (HC3A through HC30A); the 6-foot HC6A suits a short exposed riser or a crawl-space run to a hose bib. The instructions are strict: run the cable straight along the bottom of the pipe, tape it every 6 inches with tape rated to at least 176°F, seat the thermostat at the pipe's coldest end, and cover it all with no more than 1/2 inch of non-flammable insulation plus a waterproof overwrap. It protects pipes up to 1-1/2 inches. Pros: the thermostat limits running time; a simple install; many short lengths; budget price; UL and CSA marks. Cons: it can never overlap, which makes valves awkward; the 1/2-inch insulation cap; a 12-month warranty; and Frost King only recommends a GFCI, where the CPSC says to use one every time. Best for: short, straight runs of supply pipe in a crawl space or garage.

3. Best for long runs — a thermostat cable up to 80 feet

EasyHeat's AHB line works like the Frost King kit, with a built-in thermostat that turns on at 38°F and off at 45°F and a lighted plug, but it goes longer: 3-foot steps up to 18 feet, then longer lengths up to 80 feet. The 40-foot AHB-140 linked here is rated at 280 watts, enough for a long crawl-space supply line. The rules match Frost King's: run it straight, never spiral, cross, overlap, cut, or splice it, and cover it with no more than 1/2 inch of non-flammable insulation. It fits pipes up to 1-1/2 inches, and EasyHeat says the outlet must be GFCI protected. Pros: UL listed; thermostat; lengths far beyond Frost King's 30-foot maximum; a clear GFCI requirement. Cons: keeping 40 feet of cable straight and clear of itself takes planning around valves; one-year limited warranty; 15°F minimum installation temperature. Best for: long, straight runs of supply pipe in a crawl space or unheated basement.

How We Chose

We compare the category first — what a first-time homeowner actually needs from heat tape — then weigh manufacturer specifications, verified buyer feedback, and how the product type is used in real homes. For this guide we also read each maker's full installation instructions and required a testing-laboratory listing. We don't accept free products or payment for placement, and every pick names its compromise. How we research and review.

Frequently Asked Questions

Is it safe to leave heat tape plugged in all winter?

Yes, that's how it's designed to work, as long as it is listed, on a grounded GFCI outlet, installed exactly per its instructions, and inspected every fall. Thermostat models heat only when the pipe nears freezing. Frost King recommends switching its cable off at the end of the season, once air temperatures stay above 50°F. FrostGuard has no thermostat, so it's energized whenever it's plugged in.

Can you use heat tape on PEX or PVC pipe?

Yes, if the maker rates the cable for that pipe. Raychem's FrostGuard and EasyHeat's AHB (which names PEX) are rated for plastic water pipe; Frost King limits plastic to Schedule 40 supply pipe and says its kits aren't made for PVC, so choose one of the other two for PEX or PVC. Constant-wattage cables need the pipe full of water at all times, and their makers recommend wrapping it in aluminum foil first.

Can I put foam pipe insulation over heat tape?

No. The CPSC says to use non-flammable insulation such as fiberglass, not foam or vinyl that could catch fire from a failing tape, and never more than the cable's maker allows. Half-inch fiberglass wrap with a vapor seal meets that rule and the instructions for all three picks, except that Raychem calls for 1 inch over FrostGuard where temperatures reach -20°F. Ordinary foam sleeves are for bare pipe.

How long does heat tape last?

None of these makers gives a fixed lifespan, so condition decides. Replace a cable when an inspection turns up cracks, charring, discoloration, cuts, or bare wire. The CPSC also urges replacing any uncertified heat tape more than three years old. If you've just moved in and found heat tape with no listing mark or of unknown age, replace it.

The Bottom Line

Insulate, seal drafts, and keep the heat at 55°F or higher when you're away. For a pipe that still freezes, the Raychem FrostGuard is the most forgiving choice, especially on plastic pipe or around valves. For short, straight runs on a budget, choose the Frost King HC6A or the length in its line that fits. For long runs, choose the EasyHeat AHB-140 or the AHB length that matches your pipe. Whichever you buy, use a GFCI outlet, follow the maker's insulation rule exactly, and inspect it every fall.

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