HTP Troubleshooting Guide
If your HeatTape PRO isn’t working, start by checking the power supply—about 95% of heat cable failures relate to either power issues or physical damage to the cable, not manufacturing defects. The most common fixes include resetting tripped breakers, inspecting for cable damage, and ensuring proper insulation. This guide walks through the most frequent problems and their solutions so you can quickly diagnose and fix your heat tape system.
Why Isn’t My Heat Tape Getting Warm at All?
If your heat tape isn’t warming up at all, the most likely issue is that it’s not getting power. Start by checking the power supply – in many cases a tripped circuit breaker or a faulty outlet is the culprit. If the breaker has tripped or the GFCI/outlet is off or bad, the cable will receive no power and therefore stay cold. Once you reset the breaker or fix the outlet, the heat tape should start warming.
However, if you’ve confirmed the power is on and the tape still doesn’t get warm, then the cable itself is probably damaged or failed. In that case, no amount of resetting will help – the heat tape likely needs to be replaced. According to the manufacturer, about 95% of “failed” heat cable calls turn out to be either power supply issues or physical damage to the cable, not a factory defect. In short: ensure it has power first; if it does and still no heat, the cable has likely reached the end of its life (or has an internal break) and you should consider testing or replacing it.
Why Is Only Part of My Heat Tape Working?
If one section of the heat tape is warm but another section is not, it almost always means the cable is physically damaged at the point where it goes cold. In a self-regulating heat tape like HeatTape PRO, an internal break or water intrusion will prevent that segment from heating, even while the rest of the cable before the break might still get warm. Common causes are a cut or nick in the jacket, a crushed/kinked section, or any breach that lets water into the cable, which effectively “kills” the heating circuit beyond that point. Unfortunately, once a part of the cable is compromised, you cannot restore heating to that segment.
The only reliable fix for an unheated section is to replace the entire cable. The manufacturer explicitly warns not to attempt patching a widely used or water-damaged cable – “If the damaged area has been exposed to any moisture, a repair will not be effective and you will have to replace your heat cable.” (In rare cases of brand-new, dry damage – say you accidentally cut it during installation but no moisture entered – there is a special splice kit available to mend that spot. However, this only applies if you are absolutely sure the interior is still dry. For any older or weather-exposed damage, replacement is the safest solution.)
Why Does My Heat Tape Keep Tripping the Circuit Breaker?
If the circuit breaker keeps tripping whenever you use the heat tape, there are three common causes to investigate:
Overloaded Circuit: HeatTape PRO draws significant current, especially on cold startups. If you have too much heat cable on one circuit or other appliances on the same circuit, it may exceed the breaker’s capacity. An overloaded circuit will trip the breaker as soon as the cables draw power. The solution is to reduce the load: unplug other devices or put some of the heat tape on a different dedicated circuit. The manufacturer advises not to run heat cable on a shared circuit with other devices. In practical terms, if you hear a buzz or hum and the breaker trips when the tape powers on, that’s a sign the circuit is at its limit and needs to be split or upgraded.
Damaged Cable Causing a Short: If the heat tape’s insulation is compromised (for example, nicks or cracks in the cable from wear and tear), moisture can get in and create a short-circuit or ground fault. A shorted cable will immediately trip the breaker (or a GFCI) to protect the system. In this scenario, the tripping is actually a safety feature – it means the cable is likely damaged and potentially dangerous. You should inspect the full length of the cable for damage. A cut or crushed section, often caused by roof edge abrasion or animal chew marks, could be causing a direct short. If you find damage, replace the cable (do not use it in a compromised state).
Defective or Oversensitive Breaker: Sometimes the issue isn’t the cable at all but the breaker itself. A worn-out or faulty circuit breaker might trip even if the load is within limits. Heat tape systems often run for long durations, which can stress an old breaker over time. If you’ve ruled out overloads and cable damage, consider that the breaker may need replacement. Replacing the breaker (or having an electrician evaluate it) can resolve nuisance trips if the breaker was simply weak or overly sensitive. Always ensure the breaker amperage is appropriately sized for the total wattage of your heat tape runs as well.
Why Did My Pipe Freeze Even With Heat Tape Installed?
It’s frustrating to have a pipe freeze despite heat tape being in place. In our experience, this usually comes down to one (or more) of three issues:
No Power to the Cable: The heat tape might have lost power without you realizing. If the tape was unplugged, or a breaker/GFCI tripped earlier, the cable would not have been heating the pipe at all. This is the first thing to check – make sure the system actually had power throughout the cold period. Many times a homeowner discovers the breaker was tripped or the outlet was dead, meaning the tape never turned on. In short, a powered-off heat tape can’t prevent a freeze (an obvious but common oversight).
Poor or Wet Insulation on the Pipe: Heat tape alone isn’t enough; the pipe also needs to be properly insulated on top of the cable. If your pipe’s thermal insulation was inadequate, missing in spots, or became wet, the heat retention drops dramatically. Wet insulation, in particular, conducts heat away and renders the heat tape far less effective. Radiant Solutions emphasizes that the pipe must be 100% covered with dry insulation wherever heat tape is applied. Use a minimum 1/2″ thickness standard pipe insulation. If your pipe froze, check that the insulation is intact and dry along the entire run. Any waterlogged or thin insulation should be replaced or augmented. Essentially, the heat tape needs that insulation to trap its warmth around the pipe.
Insufficient Cable Coverage or Output: In very cold climates or for large-diameter pipes, a single run of heat tape might not output enough heat to prevent freezing. HeatTape PRO is self-regulating (about 6–10 watts per foot depending on conditions), but extreme environments can overwhelm a lone cable. For example, a 2-inch PVC water pipe in sub-zero temperatures may require more than one cable run. The manufacturer notes that in some cases – especially plastic pipes, pipes over 1″ diameter, or extreme cold – you may need to add a second line of cable to provide adequate freeze protection. If your pipe froze, it could be that the heat tape’s length or wattage was not sufficient for the pipe’s length and conditions. Ensure you have the correct length installed (including extra for valves or spigots) and consider doubling up cables or increasing insulation for very challenging situations.
By addressing these points – confirming the cable had power, improving insulation, and verifying sufficient coverage – you can greatly reduce the chance of future freezing with the heat tape system.
Quick Troubleshooting Reference
| Issue | Most Likely Cause | Quick Fix |
| Entire cable not heating | No power or tripped breaker | Check breaker, outlet, and GFCI |
| Part of cable not heating | Physical damage to cable | Inspect for cuts/damage; replace cable |
| Breaker keeps tripping | Circuit overload or damaged cable | Move to dedicated circuit; inspect cable |
| Pipe still froze | Power loss, poor insulation, or insufficient coverage | Verify power, add insulation, consider second cable |
| Green light not on | Defective LED (not critical) | No action needed if cable feels warm |
| Snow covering cable | Normal operation | Check for melted channels underneath |
Is It Normal for Snow to Still Cover My Heat Tape?
Yes – it’s completely normal to see snow remaining over an active roof heat tape. In fact, a layer of snow on top of the cable often forms a small insulated tunnel around it, sometimes called “iglooing.” This is not a sign of a problem at all. The purpose of HeatTape PRO is not to melt every bit of snow on your roof; rather, it melts channels or pathways through the snow and ice. As long as the cable is creating melted water run-off paths (for example, you see grooves in the snow/ice or water trickling away), it is working as intended.
Keep in mind that HeatTape PRO only warms to a modest temperature. It’s designed to get warm, not hot – typically it maxes out under about 100°F (which is just slightly above body temperature). That gentle heat is sufficient to carve through ice and prevent ice dams, but it won’t instantly melt all the snow on contact. So seeing snow still blanketing the cable is expected. In short, snow-covered heat tape is normal because the cable operates by tunneling through the snow rather than clearing it completely. As long as you have those melted “tunnels” or edges where water can flow, your heat tape system is doing its job.
What If the Green Light Isn’t On But the Cable Feels Warm?
HeatTape PRO comes with a built-in green indicator light (GlowCap) on the end of the cable. This LED is there for convenience, to show at a glance that the cable is powered. If you notice that the green light isn’t illuminated, but the cable itself feels warm, don’t panic. The heat tape can still be working perfectly even if the light has failed. The green LED is not required for normal operation – it’s just an indicator.
In other words, warm cable = working cable. If the cable is warm to the touch (or you observe it melting ice/snow), then it is definitely receiving power and heating as it should. A burnt-out or malfunctioning GlowCap LED doesn’t affect the heating performance at all. The manufacturer notes that the LED is a “convenience feature” – if the cable is doing its job, “there is no corrective action to take” just because the light isn’t on. You can continue to use the heat tape normally. (If it really bothers you, the only way to fix an LED would be to replace the cable end/plug, but again, if the tape is warm, it’s working despite the indicator light.)
How Hot Should My Heat Tape Get?
HeatTape PRO is designed to get warm, not hot. Under normal operation, it will feel warm to the touch – but never so hot that it would burn you or damage surfaces. In fact, the manufacturer specifies that HeatTape PRO “will never get hot to the touch. It is meant only to get warm. If the cable feels warm it is working!” This means you shouldn’t expect the cable to feel like a heating element or a hot pipe; it usually feels just mildly warm (especially in milder weather).
At full output in very cold conditions, the surface temperature of the cable might approach 80–100°F, but that’s about it. This gentle warmth is by design. It provides enough heat to prevent ice accumulation and freeze-ups without running up the temperature excessively. In fact, because it self-regulates, when the ambient temperature is close to freezing, it may only feel a little warm or even neutral to the touch. The key point: not feeling “hot” is normal. As long as you can detect some warmth (in freezing conditions) or see it melting ice, the heat tape is reaching the proper temperature. It will never be scorching, so you don’t have to worry about it overheating your pipes or roof. Slight warmth equals normal operation.
Unlike constant wattage cable found in big-box stores, which can get dangerously hot and can’t be overlapped, HeatTape PRO’s self-regulating technology adjusts heat output based on temperature. This means it only uses the energy needed and never gets hot enough to cause damage – even if the cable overlaps itself.
Can I Repair a Damaged Section of Heat Tape?
Repairing a damaged heat tape is possible in very limited circumstances, but generally not recommended once the cable has been in service with damage. If the damage is small, brand-new, and the cable has never gotten wet at that spot, you can perform a repair using a manufacturer-approved splicing kit. Radiant Solutions offers a Tee & Splice Kit (TSK-723) specifically for HeatTape PRO that allows you to cut out the damaged segment and splice the cable back together. This is typically used when, for example, someone accidentally cuts or drills through a cable during installation or shortly thereafter – and crucially, you know no water has infiltrated the cable’s inner layers yet.
However, if the damaged area has been exposed to moisture, all bets are off on repair. Once water or ice works its way into the cable’s core, the self-regulating matrix and conductors start to degrade. In that case, even a splice repair might not hold up (or could be unsafe). The manufacturer explicitly warns that if any moisture has gotten in, “a repair will not be effective and you will have to replace your heat cable.”
So, the rule of thumb is: repair only fresh, clean cuts (using the proper kit and following instructions meticulously). For any older or suspicious damage – especially if the cable has been through a winter with that nick – the safest solution is to replace the entire cable. This ensures the integrity of the system and maintains the warranty and safety ratings. When in doubt, err on the side of replacement, as compromised heat tape can fail or trip breakers if not fully sound.
What Are the Most Common Causes of Heat Tape Damage?
HeatTape PRO is built rugged, but there are several common hazards that can damage any heat tape over time:
Rodents Chewing the Cable: By far one of the most frequent causes of damage is animals gnawing on the cable. Rodents (especially squirrels and mice) find cable coatings attractive to chew, and they can bite through the outer jacket and even the inner conductors. Even a “slight damage” from a squirrel’s teeth can ruin a heat cable, necessitating replacement. If you have squirrels on the roof or rodents in the area, this is a prime suspect. Some people will install conduit or use repellent tapes in areas with heavy rodent activity to protect the cables.
Accidental Damage During Maintenance: A lot of heat tape injuries happen during roof or gutter maintenance. For example, roof snow removal is a big one – using a roof rake or shovel to clear snow can inadvertently cut or snag the heat tape if you’re not careful. Similarly, cleaning gutters, installing holiday lights, moving ladders, or any other work on the roof can lead to cable abrasion or cuts. The cable can get crushed or pinched by tools or fasteners if someone steps on it or presses it against sharp edges. Always be mindful of where the heat cables are when doing any work on the roof. If hiring contractors (roofers, painters, etc.), remind them about the presence of heat tape so they don’t accidentally damage it during their work.
Downspout and Yard Equipment Damage: The ends of downspouts are another problem area for heat tape. Cables often run through gutters and then exit at the bottom of downspouts, where they can be hit or cut. In fact, the mouth of a downspout is so prone to cable damage that Radiant Solutions sells a Cable Guard to shield the cable there – they note that heat cables at downspout openings are frequently damaged without such protection. The causes here include the sharp metal edge of the downspout rubbing against the cable, ice movement shearing it, or even landscaping equipment hitting it. For instance, a weed trimmer or lawn mower near the bottom of a downspout can easily catch the exposed cable and rip it. It’s important to secure and protect the cable at those vulnerable transition points. Use a protective conduit or guard at ground level and avoid running a string trimmer right next to where the cable emerges.
In summary, most heat tape failures can be traced back to physical damage: whether by critters, by human error, or by environmental wear and tear. Keeping an eye out for these common hazards and taking preventive measures (like using cable guards and exercising caution during maintenance) will greatly extend the life of your HeatTape PRO system.
When to Call for Professional Help
While many HeatTape PRO issues can be resolved with basic troubleshooting, some situations require professional assistance:
- Persistent breaker trips after checking for obvious overloads
- Inability to locate the source of cable damage
- Need for electrical work to add dedicated circuits
- Questions about proper installation or system sizing
- Any situation where you’re uncomfortable working with electrical systems
If you need help troubleshooting your HeatTape PRO system or want to connect with a professional installer in your area, contact us at 877-387-4218. We’re here Monday through Friday, 8 AM to 5 PM Central Time, and we actually know this stuff – we’ve been solving ice dam and freeze prevention problems for over 35 years.