In a detached garage mount it on the wall below the heater.
Install thermostat wall heater.
If you have an attached garage mount the thermostat on the common wall between the garage and the house and away from the heated airflow.
Most new thermostat units are compatible with heat pump thermostats baseboard heater thermostats furnace thermostats and boiler thermostats.
If you have two or more heaters in a large room place the thermostat in a central location.
Connect the low voltage wires to the appropriate screw terminals on the new thermostat base if your connections do not match consult the installation diagram in the new thermostat s owner s manual.
It s easiest to mount a thermostat used with a wall heater in the same stud cavity on the opposite side of the stud about five feet above the floor.
You ll need to identify if your home is fitted with 1 stage 2 stage direct line voltage 24mv or zone heating and cooling to determine which thermostat will be compatible.