Floor Sensor Compatibility & Installation

Last updated: May 21, 2026

Floor Sensor Compatibility & Installation

Mysa for In-Floor Heating works with the included sensor or most existing floor sensors. This flexibility means you can use your current sensor or install a backup.

Included Sensor

| Specification | Value |

| Type | 10K Ohm at 25°C |

| Length | 15 ft (3m) |

Compatible Third-Party Sensors

Mysa works with any floor sensor in the 5K to 40K Ohm resistance range. You can:

  • Use your existing floor sensor from a previous thermostat
  • Install a longer sensor for larger rooms
  • Use a different brand's sensor

Tip If purchasing a replacement sensor, a 10K Ohm sensor at 25°C provides the most accurate readings without calibration adjustments.

Calibrating Your Floor Sensor

If you're using a sensor that isn't 10K Ohm, calibrate it in the app:

  1. Open the Mysa app
  2. Tap the In-Floor thermostat
  3. Tap Settings
  4. Tap Floor Sensor
  5. Select your sensor's resistance value
  6. Tap Save

Mysa automatically adjusts temperature calculations based on your sensor resistance.

Installing a Backup Sensor

Many professionals recommend installing a secondary sensor during initial floor installation.

Why install a backup:

  • Floor sensors occasionally fail over time
  • Replacing a sensor under flooring is expensive and disruptive
  • A backup sensor can be connected without accessing the floor

How to install:

  1. Run the backup sensor cable alongside the primary sensor
  2. Position the sensor tip in the same area as the primary
  3. Leave the wire ends accessible in the electrical box (don't connect yet)
  4. If the primary sensor fails, disconnect it and connect the backup

Sensor Error Code: I3

If you see error code I3, the floor sensor has an issue:

  • Sensor wire disconnected
  • Sensor damaged
  • Sensor resistance outside 5K–40K Ohm range

See the Error Codes article for troubleshooting steps.

Need Help?

Contact our support team at support@getmysa.com