Heating tape freeze protection for pipes: questions & answers

Here are frequently-asked questions (and replies) on the use of heat or heating tapes to protect pipes from freezing.

This article series explains where, why, and how to add heat at cold problem spots to avoid freezing pipes - both supply pipes and drain pipes. We also point to information on using heating cables on heating oil piping and in in other locations. We discuss the safe use of heat tapes in buildings and warn about unsafe heating tapes and fire hazards.

Q&A on Using Heat Tapes & Cables to Protect Pipes From Freezing

Recent questions & answers about using heating tapes on pipes, posted originally

at HEAT TAPES to AVOID FROZEN PIPES - trust me, you will want to review the advice given there.

[Click to enlarge any image]

On 2021-07-15 by George - questions about installing Easy Heat heating cablews

Apparently heavily insulating over a self-regulating heating cable that calls for minimal insulation can be a bad thing. EasyHeat calls for only 1/2" of fiberglass wrap on their self-regulating pipe heating system, and the safety tag on the product cord says to not over-insulate.

So, I called and talked to the tech service guys. They said that more insulation is not a fire hazard, but while it will keep the heat in, will cause the cable to regulate the heat downward and can then allow the pipe to freeze. The system is designed to keep the pipe from freezing within the engineered temp range without extra insulation.

Interesting contrast to Raychem, that instructs a "minimum" of 1/2" of insulation for their self-regulating FG1 product. Their instructions and on-line images also show using foam pipe insulation, while the safety tag on the product warns to use only non-flammable insulation like fiberglass.

EasyHeat also calls for non-flammable insulation. I'd think the Raychem product would suffer the same downward self-regulation as the EasyHeat product.

On 2021-07-15 v - by (mod) - don't over-insulate heating tapes in violation of the manufacturer's instructions

@George,

Thank you for that helpful comment;

I repeat your information and add more details at our main page on this topic

HEAT TAPES to AVOID FROZEN PIPES https://inspectapedia.com/plumbing/Pipe_Heat_Tapes.php

on that page at

INSULATION as PIPE FREEZE PROTECTION

and will be grateful for your further thoughts.

On 2018-08-19 by John Buzza - Can I run an Easy Heat braided cable through a floor joist below a PEX cold water line?

Can I run an Easy Heat braided cable through a floor joist below a PEX cold water line?

I’ve attached a picture of the installation but am worried that the tape could cause the joist to char.
IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2018-08-19 by (mod) - EasyHeat SR Trace Cable for pipe freeze protection

Illustration: EasyHeat SR Trace Cable for pipe freeze protection, described by the company as

John,

Emerson's EasyHeat braided cable is described by the company as

Can be wrapped over itself (overlapped), if necessary, when installed on pipes, valves or flanges

Cables are rated at 3 Watts per 1 ft (0.30 m), +10 °C (+50 °F); 22.86 m (75 ft) maximum circuit length, 3 ft (0.91 m) minimum circuit length

That's not going to char a joist.

The actual temperature that these cables will impart to a surface they touch can be measured in energy or watts but giving an absolute temperture in degF or degC is more difficult as the ambient air temperature and the temperature of the contacted surface as well as - in this case - the temperature of the water in the PEX piping and the heat transmission properties of PEX all combine to say - "can't say exactly".

Sources I checked confirm that you can use heat tapes on PEX but you might check the PEX specifications for tolerance of heat exposure as you could weaken or damage the PEX tubing leading to a leak.

I doubt there's a problem: typically PEX can tolerate 240DegF. Where PEX tubing is used for radiant-heat under-floor tubing, 125 to 130 °F is typical.

See DAMAGE CAUSES in PLASTIC PIPING - why do plastic pipes leak? - to confirm this opijnion.
Original IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed Sorry. Mod.

Also see this

• EASY HEAT HEATING CABLE CATALOG [PDF] (2020) Emerson Products, Emerson US and World Headquarters | Emerson Electric Co. 8000 West Florissant Avenue, P.O. Box 4100, St. Louis , MO 63136, United States Tel: +1 314 553 2000 + 1 888 889 9170 offices world wide, retrieved 2021/07/15 original source: https://www.emerson.com/documents/commercial-residential/easyheat-residential-commercial-solutions-catalog-en-2125080.pdf

On 2019-01-31 by bvorobel@yahoo.com - signs of frozen water supply line at Marshfield mobile home

A plumber replaced the water intake pipe to the mobile home, wrapped it with heat tape/cable and insulated it. This weather has been 22 degrees below zero for two to three days now with wind factor of 40 degrees below or more.

The mobile home is 25 years old Marshfield with the old fashioned vinyl skirting. Water pipes froze since there is no water in the home.

The plumber did the work about 4 years ago and everything was fine. This winter is the coldest it has been almost EVER. Is it possible this cold could still freeze intake water pipe even with heat taped? How cold is heat tape/cable good for and for how long ? One day of very cold days and night Or not at all good when it is that cold on a mobile home?

On 2019-01-31 - by (mod) -

I agree that given the unusually cold conditions it's entirely possible that your waterline has frozen just as you suspect. Often a careful inspection will find one or two vulnerable spots such as at an elbow or bend that's poorly insulated. Sometimes you can restore Flow by following those points.

Since weather extremes including extreme hot and extreme cold are likely to be more frequent in our future as a feature of climate change, it makes sense to take more steps to try to Frostproof or Freeze Proof these lines.

On 2017-10-05 by Susan Cotton - tell me specifically where i need to put heat tape for my mobile home

without having to read ALL the MILLIONS of different articles, can you tell me specifically where i need to put heat tape for my mobile home?

On 2017-10-05 by (mod) - where to put heat tapes

@Susan Cotton,

Put heat tapes on water supply and drain pipes, faucets, controls, that are exposed to freezing temperatures anywhere in, on, or under your home.

Beyond that general advice, as I don't know a thing about your home, its country, city, climate, construction, plumbing, plumbing routing, pipe locations, specific points of draft or cold air that might freeze even an indoor pipe, I can't be more specific.

But your question is a good one; at our article on this topic (your question is posted on the article's FAQs page) - HEAT TAPES to AVOID FROZEN PIPES inspectapedia.com/plumbing/Pipe_Heat_Tapes.php

you will find

LOCATIONS for HEAT TAPES for FREEZE PROTECTION - where to put heating tapes

our best suggestions; it's just one section of one page, not millions of pages, so please take a look and do let me know what questions you have after that.

On 2017-02-13 by Anonymous

Just wonder if there 's a way to insulate PVC condesate drain . 90 + furnace without the foam rubber insulation melting

On 2017-02-15 by (mod) - Insulate PVC drains

Insulate PVC drains - worried about foam insulating melting? I'd be surprised if condensate drains reach a high temperature in the first place; what am I missing?

On 2016-12-15 by Paul - can you use freeze free heat tape under a mobile home on the main water line with PEX tubing?

i have a question can you use freeze free heat tape under a mobile home on the main water line with pex line

On 2016-12-17 by (mod) - Take a look at the specs for the heating tape you are examining.

Paul:

Some heat tapes yes, many, no.

Take a look at the specs for the heating tape you are examining. Many products specifically warn against using heat tapes on plastic piping.

On 2016-12-06 by bob - Can heat tape be used to keep oil lines from freezing ?

Can heat tape be used to keep oil lines from freezing on an outdoor oil tank

On 2016-12-09 by (mod)

Bob:

Yes in some circumstances and with the right tape but else there's a risk of fire.

See details at https://InspectAPedia.com/oiltanks/Oil_Piping_Heat_Tapes.php

On 2016-10-20 by Ruth - how much clearance space do I need around a pipe wrapped with heat tape?

There is about a two inch space between the inside wall and outside wall where my copper pipe feeds from the pump (inside) and exits with an elbow before going underground (at a good depth) to service water to the house. Is there a safe clearance I can make around the pipe to use heat tape? Thanks!

On 2016-10-20 by (mod)

Ruth, in general, yes, two inches should be enough clearance space, but the full and correct answer will be in the heating tape installation instructions for the *specific* brand and model of heat tape that you plan to use.

On 2016-09-14 by Chuck - can I use one continuous pipe heating c\able along three separate water lines?

I have three water lines coming out of my house each with a shut off valve. They are about 6 inches apart.

I open these valves before the winter sets in to drain all the water out of the lines. This winter I'll be staying in the house and wanted to use self regulating heat tape on these three lines and valves.

I was hoping to use one continuous self regulation heat tape line to cover all three water lines. If I wrapped one line can I go over to the next line and leave a loop between the lines? Then continue over to the third line with another loop.

Any suggestions would be greatly appreciated. Thanks. Chuck

On 2016-09-16 by (mod)

Yes you can do that provided the heat tape is rated for outdoor use and wrapped and insulated as instructed by the manufacturer. Some tapes can be crossed over themselves safely, others not.

On 2016-01-24 by Brenda - can insulation alone prevent pipes from freezing

in our cold Michigan winters I need to know if insulation alone can keep a mobile home pipes from freezing or if heat tape is also needed.

I myself don't think insulation alone can do the job but I do think that heat tape can..
Can someone let me know.

On 2016-01-24 by (mod) - yes for a short time, no for longer cold periods.

Brenda,

It depends on where the pipes are located and what heat source is available. For example pipes running under a mobile home or in an un -heated crawl area will be less likely to freeze if insulated but are not absolutely freeze protected unless you add a heat tape.

That's because in an area without heat, as that area becomes cold, insulation on piping slows the loss of heat from the pipes into the cold area - thus slowing the rate of freezing. But it cannot stop it completely.

So insulation alone may protect pipes from freezing if the pipes are exposed to very cold conditions for a few hours, but not if the same cold continues for a day or longer.

On 2016-01-04 by Eric - is it safe to install heat tape around pipes inside walls?

Thanks for lots of information. One thing I'm looking for that seems missing - is it safe to install heat tape around pipes inside walls? (i.e., exterior walls that drop below freezing). I've read some articles that say it is against code, as it presents a fire hazard, but haven't been able to confirm that - any more info you might have on that?

I'm worried that heat tape installed inside a wall would be very difficult to regularly inspect, and could cause a fire in combination with wood framing, insulation, etc. - thank for any adivce.

On 2016-01-04 by (mod) - I would not install heat tape inside of a wall

Thanks for the question, Eric.

Watch out: I would not install heat tape inside of a wall even if some folks think that's safe. Indoor heat tapes are rated to be covered with insulation, that's not the issue. It's that I NEVER want to install a type of electrical wire not intended for permanent installation inside of a wall or ceiling cavity where it can't be seen.

The risk is intermediate or even long term deterioration, insulation cracking, and a fire. The classic example is the use of extension cord wire run through a wall cavity to add a light fixture up on a wall. Don't do that.

If pipes in an uninsulated wall cavity are exposed to freezing I'd probably pump insulation into the wall or take another approach to protecting them. We can elaborate that if needed. Or search InspectApedia.com for FREEZEPROOFING to see a series of articles that includes discussion of finding pipe freeze points such as where there area drafts or cold spots.

On 2015-12-13 by terry - can a heat tape prevent gutter freeze-up?

I have a problem with the lip of my leaf guard gutters freezing and when the ice build up melts it misses the gutter . can I use one of your cables or tapes to heat the curve of this system to avoid a ice build up

On 2015-12-13 by (mod)

Yes, Terry but to be clear, they're not "my" cables.

At your local hardware supplier or building supplier you'll see heat tapes that are specifically designed, rated, listed and approved for use outdoors, exposed to the weather, to prevent gutters and downspouts from freezing-up.

To protect reader trust InspectApedia.com does not sell any product nor service and we have no business nor financial relationship with products or services that we discuss at this website.

On 2015-12-12 by Dave - will the heat tape cause water in pipes to evaporate and start a fire?

I have heat tape on PVC in my garage. If I turn the water off at the main in preparation for a trip, is there a danger that the water in the PVC will evaporate and cause the heat tape to cause a fire?

On 2015-12-12 by (mod)

Dave

The hazard is not that the water in the pipes will evaporate - unlikely over any interval of months - but that the heat tape was not designed for use on plastic piping.

If your heat tape was not intended for use on plastic pipes you risk melting the pipe, flooding the building, and causing thousands of dollars of damage before any fire hazard.

Question: is it OK for the water line to run atop a concrete slab or should it be under ground?

In a mobile home in N.E. should the water supply line be placed on top of the concrete slap for 30 feet or more.

Would that be up to code? Should the line from the street be 4 feet under ground to within 6 feet of the hot water heater? - Lee Broad 1/23/12

Reply:

Lee, if you are describing a water line atop the rat slab beneath a mobile home, there are a couple of hazards including freezing and also movement-caused abrasion and leakage.

If the line is supported off of the slab by blocks and insulated you may be OK, else you'll need to add frost protection as well.

Heating cables (see advice above in this article) are readily available in lengths up to 60 ft. so you won't have trouble finding one long enough. Don't buy a heating cable longer than you need and be sure it is connected according to the manufacturer's instructions.

Watch out: do not bury a heating cable or any other electrical component in concrete before checking with the manufacturer that that application is approved.

...

Continue reading  at HEAT TAPES to AVOID FROZEN PIPES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see HEAT TAPE PIPE PROTECTION FAQs-2 - more-recent Q&A about preventing pipe freeze-ups

Or see these

Pipe Freeze Protection Articles

• PIPE FREEZE PROTECTION - home
  • DRAIN FREEZE PROTECTION
  • HEAT SOURCES to AVOID FROZEN PIPES
  • INSULATION to AVOID FROZEN PIPES
  • PIPE FREEZE-BURST PATTERNS
  • PIPE FREEZE-UP POINTS
  • PIPE INSULATION CHOICES, MATERIALS, TYPES
  • WELL SNIFTER & DRAIN BACK VALVES
• WINTERIZE A BUILDING - home

Suggested citation for this web page

HEAT TAPE PIPE PROTECTION FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING FREEZE PROTECTION

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