Sealed Crimp & Solder Butt Splice Connector (SP-Crimp)

In theory, it is possible, if no other options are available. We do not recommend it, but If the thermostat is controlling the floor temperature with a floor sensor, then it can go on an exterior wall. It is important that the floor sensor gets located in an area of the floor not hit by sunshine.

If the thermostat will be controlling the air temperature with the built-in ambient sensor, then it should go on an interior wall.

WarmlyYours has recently begun including floor sensors with our heating elements to help ensure customers will have everything they need for optimal operation of their radiant heating systems.

The sensor included with your floor heating element can be installed with the heating system (the sensor is equally spaced between runs of the heating wire--see your install manual for more info). Installing this sensor with your floor heating control will enable energy efficient operation of the floor warming system based on the floor temperature instead of the ambient room temperature.

We generally recommend that you install a second, unconnected backup floor sensor alongside the primary one. In the very unlikely event that your first floor sensor is damaged, this install method will save you from having to pry up flooring to replace a floor sensor. You simply disconnect the damaged sensor from the thermostat and connect the backup sensor.

In addition to the floor sensor that was included with your heating element, our nSpiration Series thermostats also come with a floor sensor. If you purchase both a heating element and an nSpiration Series thermostat from WarmlyYours, you'll have a primary and a backup floor sensor for your system.

A digital meter with a 0-200 Ohms scale ( Ω ) to measure the heating wire's resistance, and a 20K scale to measure the sensor's resistance.

Yes, the sensor wires may be trimmed.  Most local code requirements call for 6“-7“ of extra wire from the gang box.

Most of the installation — laying out the heating element, placing the floor sensor, and pouring self-leveling cement — can be completed as a DIY project by a competent homeowner. However, the final thermostat wiring connection must be completed by a licensed electrician in most jurisdictions.

WarmlyYours makes DIY installation easier with:

• SmartPlan® — a free custom layout service that maps out your exact cable placement, sensor location, and electrical requirements
• Circuit Check — a monitoring device that alerts you if the heating cable is damaged during installation
• 24/7 technical support — available throughout your installation

Always check local electrical codes before beginning any floor heating installation.

Yes, the floor sensor wire can be extended up to 300 feet with 18 AWG wire.

Yes — insulating underlayment is strongly recommended when installing electric radiant floor heating over a concrete basement slab. Without it, a significant portion of the heat will conduct downward into the cold concrete rather than upward through the floor surface where you want it.

WarmlyYours recommends ThermalSheet® insulating underlayment for basement slab installations. It improves system efficiency, reduces operating costs, and helps the floor reach target temperature faster.

Skipping underlayment on a basement slab is one of the most common — and most costly — installation mistakes.

Operating costs for electric radiant floor heating in a basement depend on your local electricity rate, the size of the heated area, and how many hours per day the system runs.

As a real-world example, a finished basement playroom in Whitchurch-Stouffville, Ontario cost approximately $0.19 CAD per hour to operate — significantly less than running a portable electric space heater, and with whole-floor comfort rather than point-source heat.

In the US, typical operating costs range from $0.01–$0.15 USD per hour depending on system size and local electricity rates. Use the WarmlyYours Operating Cost Calculator to estimate your specific project.

Electric radiant floor heating can serve as a primary heat source in a well-insulated basement, particularly for finished basement spaces used as living areas, playrooms, or home offices.

Unlike forced air systems, radiant heat warms objects and people from the floor up — which is especially effective in basements where cold radiates upward from the concrete slab. This makes it a more efficient and comfortable option than forced air in below-grade spaces.

For larger or poorly insulated basements, a heat loss calculation (available free through WarmlyYours SmartPlan®) will confirm whether the system can meet the full heating load or whether it should supplement an existing system.

This could be due to one of the following:

a.) The higher temp reading might be due to a rubber bottomed / heavy rug, or piece of furniture placed over the floor sensor. This would trap heat over the sensor making it read a higher value than the rest of the floor –- Remove the item trapping the heat over the floor sensor.

b.) If the thermostat indicates a strange, higher measurement. Then more than one (1) floor sensor may have been hooked up to the thermostat -- Disconnect the extra sensor(s) and leave just one pair of wires hooked up (terminals C+D) to the thermostat.

c.) The floor sensor calibration may have been changed -- This setting should NEVER be changed, do a thermostat factory reset: Installer and User resets to clean this up.

d.) Is the OJ Microline thermostat used on a very old floor heating system? Some of the older systems, particularly the ones using an OJ Dual / Energystat thermostat had 12kΩ sensors in the floor -- Change the installer setting to read a 12kΩ floor sensor, instead of the default 10kΩ floor sensor.

If further assistance is needed, please contact WarmlyYours technical support.