Incompatible Systems

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

Heaters with built-in controls

If your heater only has a dial on the unit itself (no separate wall thermostat), there's no gang box to install Mysa into.

24V (low-voltage) systems

These are central HVAC systems with thin wires labeled R, C, W, Y, G, or O/B. Use Mysa Smart Thermostat instead.

Hydronic (water-based) baseboards

These circulate hot water and require a boiler thermostat, not a line-voltage electric thermostat.

Gas heaters

These need a gas-compatible thermostat.

Three-phase or commercial 208V systems

Only single-phase 120V and 240V are supported. (Single-phase 208V is supported — see Wattage & Amperage Limits.)

2-wire only setups

Mysa requires 4+ wires for power. A 2-wire setup typically controls a relay or contactor and doesn't provide the necessary power configuration. This is rare — always check for tucked/capped wires in the box first. See Wiring Requirements.

Proprietary systems

Some manufacturers use specialized thermostats that cannot be replaced with a standard line-voltage thermostat.

If you have a 2-wire system specifically

• Consult an electrician — they can assess whether additional wiring can be run

• Consider Mysa for Central HVAC — if your system uses relays, this model with a C-wire adapter might work

• Look for a line-voltage thermostat specifically rated for your heater's amperage

Not sure if this applies to you?

Email install@getmysa.com with a photo of your existing thermostat wiring and heater rating plate.