Two tools that do different jobs
Foam or fiberglass pipe insulation works like a coat. It slows down heat leaving the water, which can be enough on a pipe that gets some warmth from the house, such as a line in a garage wall that is shared with a heated room. It cannot add heat. On a line in a fully unheated space through several days of arctic air, insulated water will still eventually reach the temperature around it.
Heat cable, sometimes called heat tape or heat trace, adds a small amount of warmth along the pipe. Self-regulating cables increase output as the pipe gets colder and are common on lines in crawl spaces, well houses and pump pits around Parker's acreage areas. Constant-wattage cables put out the same heat regardless and depend on a thermostat. Both need to be listed for the pipe material they are installed on, especially plastic pipe.
Insulation compared with heat cable
| Pipe insulation | Heat cable |
|---|---|
| Slows heat loss; adds no heat | Adds heat; can protect lines in spaces that stay cold |
| Good for lines near a heat source or for short cold spells | Needs power, so a winter outage removes protection |
| No power needed and nothing to fail electrically | Must follow manufacturer rules on overlap, insulation and pipe type |
| Gaps at elbows and valves leave weak points | Old or damaged cable is a known fire risk and should be replaced |
Fall check for any heat cable
Do this before the first hard freeze, ideally in October.
- Plug the cable into a GFCI-protected outlet and confirm the indicator light, if it has one, comes on.
- Look along the full length for cracked jackets, scorch marks or brittle sections.
- Make sure the cable is not overlapped on itself unless the instructions allow it.
- Check that insulation over the cable is the type the manufacturer specifies and is dry.
- Confirm the outlet it uses is not shared with a freezer or other appliance that trips the circuit.
- Write the install year on a tag. Many cables have a limited service life.
Questions to ask before adding heat cable
- Is rerouting this line into heated space a better long-term fix than adding cable?
- Is the cable listed for use on PEX, CPVC or copper, whichever this line is?
- Does this outlet location need to be added or upgraded, and does that require an electrical permit?
- How will I know if the cable stops working in the middle of winter?
- Would an alarm or temperature sensor in this space be worth adding?
General information for Parker, not a quote or professional advice. In an emergency, call 911.