Every heat cable gets a score from 0 to 100% built from six factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Cables are grouped by use, roof and gutter de-icing and pipe freeze protection, and use the same scale in both groups.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per foot of heating cable | 35% |
| Heating type | self-regulating or constant wattage | 20% |
| Thermostat | built-in thermostat that switches the cable on and off | 10% |
| Ready to install | plugs in out of the box, and roof clips included for roof kits | 10% |
| Safety | safety listing of the cable and a built-in GFCI plug | 10% |
| Warranty | warranty length | 15% |
Where the numbers come from
Length, output, heating type, thermostat, cord length, listings and warranty come from the maker’s catalog, spec sheet or product page, or the maker’s own copy on a retail listing. A safety listing counts only when the maker says it covers the cable, not just the plug. Prices are checked at Amazon and the maker’s own store, and the lowest price at a store the page links to is used.
The factors
Value is the current price divided by the heated length, in dollars per foot, on a log scale, so halving the price always counts the same. $4 per foot scores zero and $0.40 per foot full marks. The cold lead (the unheated power cord) isn’t counted in the length. A cable sold without a plug is priced on the cable alone.
Heating type is 100% for a self-regulating cable, which can overlap itself and turns its own output down as it warms, and 25% for a constant-wattage cable, which must never touch or cross itself.
Thermostat is full marks for a thermostat built into the cable or plug that switches it on near freezing and off when it warms up, and zero otherwise. A plug-in thermostat or roof controller sold separately isn’t counted.
Ready to install is whether the box has what it takes to get running. For a pipe cable it is full marks if it plugs into an outlet out of the box (pre-assembled, or a connection kit is included) and zero if a plug kit has to be bought separately. For a roof kit, plugging in out of the box is 70% and roof clips or spacers in the box are 30%.
Safety is 60% for a UL, ETL or CSA listing (or the Canadian versions) that covers the whole cable and 40% for ground-fault protection built into the plug. Most makers say to plug into a GFCI outlet, which every cable needs; only built-in protection scores.
Warranty is the maker’s warranty: 1 year scores zero and 10 years full marks.
What isn’t scored
Watts per foot, total watts, voltage, thermostat temperatures, cord length, largest pipe size and release date are listed but not scored. Higher output isn’t always better: a roof needs more heat per foot than a pipe, and a low-wattage pipe cable uses less power for the same job.
Missing data
Price and length are known for every cable, so the value factor is never estimated. A safety listing or roof clips that the maker doesn’t mention count as absent. A thermostat the maker doesn’t mention counts as none, and a maker that doesn’t publish a warranty gets no warranty counted, so that factor scores zero, the same as a one-year warranty. Both are marked estimated on the product page. If a heating type isn’t published, that factor gets the neutral middle score (50) and is marked estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.