Replacement/Backup Floor Sensor with Standard Sensor Probe

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.

Yes. The floor never free-runs — the thermostat’s floor sensor governs output, and you set a maximum floor temperature limit in the thermostat itself. Most heated tile bathroom floors are set between 80°F and 85°F. Set that limit during commissioning and record it on the handoff sheet so the homeowner does not raise it past the flooring manufacturer’s rated maximum.

Yes, but the tear-out is the real risk. Scan the floor with thermal imaging before demo to map the existing hydronic tubing, and never fasten or drill into it. Keep the two systems on fully independent controls so they cannot fight each other, and do not place the electric floor sensor directly above a hydronic loop — the false-high reading will short-cycle the electric system. Call PRO technical support at 800-875-5285 to review the assembly before ordering.

No. Electric floor heating cable is listed for installation under floor coverings only, and NEC 424.38(A) does not permit heating cable to be installed in walls. Running it vertically voids both the UL listing and the warranty. For warm towels and a little extra room heat, specify a heated towel rack, which is designed and listed for wall mounting.

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

No separate GFCI breaker is required — every WarmlyYours thermostat has a built-in Class A (5mA) GFCI. Stacking a GFCI breaker on top of it is one of the most common causes of nuisance tripping. Run a dedicated breaker sized to the load at 80% continuous duty: a 15A circuit carries up to 1,440W at 120V, a 20A circuit up to 1,920W. Loads beyond the thermostat’s 15A rating need a power module or relay.

Error code "E2" means defective, damaged, or not connected floor sensor. Check connections or replace the sensor if necessary.

Sensor resistance should be in 8kΩ-15kΩ range and can be tested with a digital multimeter on a 20k scale. If the sensor resistance is out of range, it could be damaged. Please note, only one floor sensor can be connected to a single thermostat.