Incompatible Systems

Mysa for In-Floor Heating does not work with the following systems. Reviewing this list before you buy can save you a return.

Hydronic (hot-water) floor heating

Systems that circulate hot water through tubing need a boiler or hydronic thermostat, not a line-voltage electric floor thermostat.

24V and other low-voltage controls

Thin control wires (often labeled R, C, W, Y, G, or O/B) belong on a low-voltage thermostat. Use Mysa Smart Thermostat for compatible 24V systems, not Mysa for In-Floor Heating.

Three-phase 208V

Only single-phase 120V, 208V, and 240V are supported. Three-phase 208V is not.

Baseboards, convectors, and fan-forced heaters

Those are Mysa for Baseboards products. Mysa for In-Floor Heating is only for electric floor mats and cables.

Floor heater and wall heater on the same thermostat

Do not control an in-floor zone and a wall, baseboard, or similar room heater from one Mysa for In-Floor Heating thermostat — even if the combined wattage looks like it is under the limit. See Can Mysa for In-Floor Heating control a floor heater and wall heater together?

Existing GFCI-protected circuits

Mysa has built-in Class A GFCI protection (5 mA). Do not install it on a circuit that is already GFCI-protected.

Aluminum wiring

Copper wiring only.

Forced air, heat pumps, gas, or oil

These are not electric in-floor heating and are not supported by this thermostat.

Loads above the product limit

Above 1,900W at 120V, 3,328W (16A) at 208V single-phase, or 3,800W (15A) at 240V is not a direct-wire installation. There is no Mysa power module for In-Floor. See Does Mysa for In-Floor Heating work with power modules or multiple zones?

Not sure if this applies to you?

Email support@getmysa.com with your heating system voltage, wattage, and photos of the existing thermostat wiring.