SCW-120-15A Frequently Asked Questions
Frequently Asked Questions
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Yes. The SCW-120-15A WiFi switch includes built-in WiFi and connects to the WarmlyYours SmartControl app. From your smartphone you can turn the deicing system on or off remotely, create manual schedules, and monitor system status from anywhere with an internet connection.
For automatic operation combined with remote monitoring, you can pair an automatic control (SCP-120, SCE-120, or SCA-DUAL) with the aerial sensor—the system runs itself based on real weather conditions while you can still check in remotely using the SCW-120-15A if needed for manual override.
The other controls (SCP-120, SCE-120, SCA-DUAL, SCM-DUAL, AIR-STAT) are standard hardwired controls without built-in WiFi connectivity.
In Step 2 of the process, where you attempt to connect directly to the Decora Smart Wi-Fi device that is listed in the Wi-Fi networks (it will be listed in the format of Leviton Device-xxxx), instead of connecting you receive a message stating it is "unable to connect" or simple never connects (e.g. no check mark next to the device).
If the device connects and you see this screen, skip to Decora Smart Wi-Fi device will not connect to the Wi-Fi Network or Leviton Cloud.
If the mobile device does not connect to the Decora Smart Wi-Fi device at this step, please follow these troubleshooting step:
- Make sure you have the latest version of the My Leviton App. To ensure that you are running the latest version of the app, check for a My Leviton app update on the Apple App store or Google Play store.
- If available, try using a different mobile phone or tablet running the My Leviton app. Follow Steps 1 and 2 and see if you are able to connect to the device. If you are able to connect, see if you can complete the process.
- Contact our technical support team at dssupport@leviton.com. Please include the type and model of mobile devices you are using and the model number of the Decora Smart device.
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.
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.
When the design requirement's amp draw exceeds the selected controller's capacity.
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).
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.
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.
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.
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).
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.
Yes. The WarmlyYours SmartControl (SC-MZ-TOUCH) includes built-in WiFi and integrates with popular home automation platforms:
- Amazon Alexa — voice-activate your system ("Alexa, turn on the driveway heat")
- Google Assistant — control via Google Home or Nest devices
- Nest — integrates with Nest home automation routines
- IFTTT — create custom trigger-based automations
The SmartControl also has a full-color touchscreen for local control. It supports automatic operation with an aerial or slab sensor and can be monitored and adjusted remotely from anywhere with an internet connection.
Other WarmlyYours snow melting controls (SCP-120, SCA-DUAL, SCE-120, SCV-DUAL, SCM-DUAL) are standard hardwired controls without built-in WiFi. The SmartControl is the only model with remote smartphone access.
No. WarmlyYours snow melting controls are industrial-grade devices designed to be installed indoors in a dry, protected electrical enclosure—such as an indoor electrical panel, utility room, or garage. They are not rated for direct outdoor exposure.
The sensors (aerial and slab) are fully outdoor-rated and designed to withstand harsh winter conditions. The sensor is the only component that goes outside; the control itself connects to the sensor via low-voltage wiring run indoors.
If you have questions about where to locate the control enclosure for your specific installation, our radiant experts can help you plan the best setup. Contact us for a free consultation.
Each WarmlyYours snow melting control has a maximum load rating. Common ratings are:
- 15A at 120V — up to 1,800 watts
- 15A or 30A at 240V — up to 3,600 W or 7,200 W depending on the model
Check the spec sheet for your specific control model to confirm its rated amperage.
If your snow melting installation exceeds the capacity of a single control—common for larger driveways, commercial entries, or multi-zone systems—you will need a relay panel. A relay panel uses the low-amperage signal from your control to switch high-amperage contactors, allowing a single control to manage systems far larger than it could handle directly.
WarmlyYours relay panels are available in single-zone and multi-zone configurations. Our free system design service will tell you exactly whether a relay panel is required for your project and which model is correct.
Automatic controls use sensors to monitor outdoor conditions and activate your snow melting system only when needed—so you never have to think about it. WarmlyYours automatic controls work with an aerial sensor (which detects moisture and air temperature) or a slab sensor (which measures the slab surface temperature). The system turns on when conditions call for melting and shuts off automatically when the surface is clear and dry.
Manual controls (also called contactor switches) let you turn the system on and off yourself. Some manual controls include a 24-hour timer so you can schedule fixed operating windows.
Automatic controls are strongly recommended for driveways and walkways that are difficult to monitor closely or for homeowners who want a truly hands-off experience. Manual controls are a lower-cost option suited to smaller areas or applications where the owner is frequently on-site.
Control systems determine when your snow melting system activates. Your SmartPlan™ will recommend the best option based on your project, but here are the main types:
Automatic Snow Sensors (Most Popular)
- Ground-mounted sensors detect moisture and temperature
- Fully automatic operation – System activates when snow is falling and temps are below freezing
- Energy efficient – Only runs when needed
- Best for: Driveways, walkways, and commercial areas requiring 24/7 protection
Aerial Detection Systems
- Roof-mounted sensors detect precipitation before it reaches the ground
- Pre-emptive activation – Warms surface before snow accumulates
- Best for: High-traffic commercial areas, ADA ramps, emergency access routes
Manual Controls
- Simple on/off switch or timer-based operation
- Lower upfront cost but requires monitoring weather
- Best for: Vacation homes, seasonal properties, or budget-conscious installations
Smart Controls with WiFi
- Remote monitoring and control via smartphone app
- Weather integration for predictive operation
- Usage tracking and energy reporting
- Best for: Tech-savvy homeowners who want maximum control and insights
Your SmartPlan™ will specify the recommended control system based on your climate zone, coverage area, and usage patterns.
WarmlyYours snow melting controls are available in both 120V and 240V versions, and the control voltage must match the voltage of your snow melting cable or mat.
Most WarmlyYours snow melting systems operate at 240V because higher voltage allows the cable to cover more area on a single circuit. Some smaller mats are available at 120V.
Controls are model-specific:
- 120V controls: SCP-120, SCE-120, SCW-120-15A
- 240V controls: SCA-DUAL, SCV-DUAL, SCM-DUAL, SC-MZ-TOUCH
Always verify the voltage of your snow melting cable or mat before selecting a control. If you are unsure, the voltage is printed on the product label and listed in the item specification sheet. Our radiant experts can confirm the right control for your system at no charge.
WarmlyYours snow melting cables and mats have a 10-year limited warranty against defects in materials and workmanship, subject to the installation and registration requirements in the snow melting warranty. Controls carry separate warranty terms; check the warranty for your specific model.