SM-JBOX-WM-L Frequently Asked Questions

That depends on a number of variables (like the temperature outside) but generally speaking these snow melting systems are designed to melt 1" - 3" of snow per hour. Anything above 3" per hour is typically considered blizzard conditions. 

Never cut the heating cable. A heating cable will not work if it has been cut. If the heating cable is too long, call WarmlyYours to consult with a technician who will guide you in utilizing the additional length of cable.

The material costs are similar. However, electric systems are easier to install, with fewer components and significantly lower maintenance costs. Electric systems will run for a shorter period of time to give the same level of performance but with much higher energy efficiency (typically 95%-98% efficient). Controls and sensors required for the two types of systems are very similar. Electric systems do not usually require slab insulation and do not create the concerns typically associated with hydronic systems. These concerns include, but are not limited to, return temperatures, flue gas venting, waterway shrinkage and property damage caused by leaking pipes or tubes.

When installing outdoor WarmlyYours snow melting cables for your driveway, patio, walkway, terrace, stairs, ramp, etc. - NEVER cross, overlap, or allow the heating cables to touch each other. Doing so will quickly cause a circuit failure due to excessive heat build up. Always follow the installation instructions and/or design layout plan to ensure the cable is installed with the correct spacing required for proper operation.

Yes. The manufacturer's splice that connects the heating element to the cold lead should be entirely embedded in a noncombustible material (like asphalt, concrete, or mortar) within the outdoor surface that is being heated. 

Our systems can handle low temperatures, but many controls come equipped with a Low-Temperature Lockout Feature. This feature prevents the system from running in very low temperatures. At very low temperatures it can become difficult for the system to effectively melt the snow. It is however possible to turn off this feature should you need the system to keep running during such low temperatures.

This National Electric Code (NEC) required protection for fixed outdoor deicing and snow-melting equipment may be accomplished by using circuit breakers equipped with ground-fault equipment protection (GFEP) of 30 mA. It is important to understand that this required equipment protection is not the same as a 5 mA GFCI used for personal protection.

Power requirements are measured in Amps and based on three factors: the watts per sq. ft. of the snow melting cable or mat, the area powered and the voltage used for the application. Our product is rated at 50 watts per sq. ft., so that is a constant factor. Most snowmelt projects are powered with 240V AC – not all, but most. The one factor that is always variable is the area to be heated/powered. That is based on your project. For a point of reference, let’s use the example above of a 350 sq. ft. concrete patio.

The formula is (50 W/sq. ft. x area of 350 sq. ft.) / V (240V) = Amps, so 17,500 / 240V = 72.9 Amps

All of our automatic controllers have a Hold-on time feature after the initial warming up of the snow melt system. This feature ensures that all the snow is melted from the surface, and also that the system continues to operate and evaporate the surface water without it refreezing.

The heating elements for a snow melting system typically will start at $9 ($11 CAD) per sq. ft. for Snow Melting Cables and $11 ($14 CAD) per sq. ft. for Snow Melting Mats. However, you'll also want to keep in mind the cost of a control, and if required, sensor/s for your snow melting system, which will add to the cost. Use our free Quote Builder to get an idea of how much a system would cost for your project. 

Pavers can be removed and reinstalled for a retrofit application of our snow melt system. Tire tracks are not typically recommended for paver surfaces, so any retrofit application would most likely need to be full coverage. In this case, it should be treated like a brand new installation, just with existing pavers.

This type of installation should not significantly affect the longevity of the driveway. Be sure to have a professional for your surface material type evaluate this during installation.

To ensure optimal performance, snow melting heating elements should be installed so that they are consistently 2"-3" from the finished surface. For installations using pavers, the maximum thickness for pavers installed over heating elements is 2.5". 

When the design requirement's amp draw exceeds the selected controller's capacity.

If a cable is damaged during installation, recheck the system for continuity and confirm the integrity of the insulation with a megohmmeter, or "megger" tester, referring to the installation and testing instructions. If the cable fails any of these tests, take the following actions: clear a 3 foot square working area around the damaged section of cable, and record the cable part number from the UL tag and the location where you purchased the product. Call WarmlyYours with the above information. WarmlyYours will provide further assistance and supply a splice kit suitable for repairing the particular cable.

To calculate the system's approximate operating costs, multiply the total kilowatts of the system by the cost per kilowatt in your area. Let's use the example of a 350 sq. ft. of concrete patio (residential application), with 240 VAC.

Total Watts: multiply area in sq. ft. x 50 Watts
350 x 50 = 17,500 Total Watts

Kilowatts: (the unit in we purchase electricity) take the Total Watts and divide by 1000
17,500 Total Watts / 1000 = 17.5 Kilowatts.

Kilowatt Rate: use the national average of .12 cents per Kilowatt-hours so how much do we pay for 17.5 kWatts?
17.5 kW x .10 = $1.75 for every full hour of operation.

Hours of Operation: We use a typical 6 hour snowfall for our example.
$1.75 x 6 hours = $10.50 for that snowfall.

All of this will vary due to "after-run time". "After run time" is where the system remains on extra hours after the snow has completed falling, to ensure complete pavement snow melting and drying.

The layer of noncombustible material needed below snow melting heating elements must be at least 2" deep. 

Each heating cable comes with a factory installed cold lead wire that must be routed through the rigid metal 3/4" conduit to a outdoor rated junction box where a simple wire nut connection can be made for the electrical hook-up.

Always confirm the power requirements with the electrician. Large snow melting systems usually require a new electrical panel or electrical service. Contact WarmlyYours for a quotation, indicating the actual power capacity available, and to obtain recommendations for reducing the power consumption. For example, opting for tire track coverage rather than installing the snow melting system over the entire driveway can dramatically reduce power requirements.

Once you've decided what type of heating system (manual vs. automatic), you'll need to choose a control, which may or may not utilize a sensor. You may need a relay panel(s) depending on the size of the system, and a snow melt plaque which is required by the National Electric Code. Junction box(es) may be optional depending on the distance of heating cable from the indoor power location.

The snow melting system is not operated by a thermostat, it is operated by either an automatic or manual controller.  A snow melting controller does not maintain temperatures like an indoor thermostat does.  An automatic snow melting controller only turns the snow melting system on when it detects precipitation and the temperature outdoors is below the set temp (typically 37.4°F / 3°C).

Small In-Ground Snow Melting Junction Box can accommodate 1 or 2 cold leads, while a Large In-Ground Box can accommodate between 3 to 8 cold leads. A large Wall-Mounted Junction Box can accommodate up to 8 cold leads.

A properly designed and installed system will handle most snow melting demands. Some snow events may have a very rapid snow fall rate, and some may not. No 2 events are ever exactly the same. Our system typically can melt 1“-2“ of snow per hour, on average. However, it is important to understand that a system may not melt snow at very cold temperatures. This is simply because the system cannot generate enough BTUs to overcome the heat loss generated by very low temperatures.
In order to estimate cost of operation, the Warmly Yours Electric Snow Melting Operating Cost Calculator is a useful tool that can help illustrate what it would cost to operate the system.

No, a sensor is not required with the snow melt system. However, certain automatic controllers require a temperature/moisture sensor to sense atmospheric conditions and may also require an in-slab, high temperature limit sensor to be installed (notably, asphalt installations).

It depends on how the system is intended to operate. If the expectation is manual operation (ex. WiFi or Timer Control), then no sensors are required. If the expectation is automatic operation, then the system will require at least one snow sensor.

For SM-JBOX-IG-S and SM-JBOX-IG-L: 

The foam-in-place gasket lids are secured to the base with stainless steel screws. 

For SM-JBOX-WM-L:
The hinged cover clamps to the base with keyed quarter turn latch for a watertight seal. 

For SM-JBOX-IG-S and SM-JBOX-IG-L: 
These boxes are made of durable PVC/PPO thermoplastic for corrosion resistance. The color of these boxes is ANSI 61 gray color. 

For SM-JBOX-WM-L:
This junction box is made of seam welded 16 ga. stainless steel with a smooth gray external finish with a clear zinc plate on the interior. 

Ground fault equipment protection (GFEP) is intended to provide protection for equipment against damaging line-to-ground currents by disconnecting all ungrounded conductors of the faulted circuit.

This feature prevents the snow melting system from running, by default, in temperatures below 17°F (–8.33°C), or as set by the user. At temperatures this low, it becomes difficult for the system to effectively melt the snow. It is, however, possible to turn off this feature should the system be required to keep running during these low temperatures.

For SM-JBOX-IG-S and SM-JBOX-IG-L: 

These junction boxes are CSA certified and UL listed. Additionally, they have the following NEMA ratings: 1, 2, 4, 4X, 12 & 13, 6P. 

For SM-JBOX-WM-L:
This junction box is UL listed and has the following NEMA ratings: 1, 2, 4, 4X, and 12.