No batteries no power stealing. Single pole thermostats only have a low setting and no true off setting and break only one side of the heaters power line.
Install Your Own Line Voltage Baseboard Heater Thermostat
Difference between single pole and double pole thermostat. Just like a single pole thermostat a double pole thermostat is wired directly to the main circuit breaker but will have four wires instead of two. Typically this is marked l1 or line step 8. Unlike the single pole setup the power supply of a double pole isnt directly tied to the heater its powered by a separate circuit. They typically have two 2 connection wires. There is another difference between single pole and double pole thermostats. The basic difference the very basic difference between a single pole and double pole thermostat is a single pole thermostat cannot be turned off completely.
Single pole thermostats can be set to a low setting but cannot be turned completely off. If the temperature falls below that setting the thermostat will turn on the heater. Theres a switch in the thermostat that completely shuts off power to the heater. If you have more than four wires coming out of your thermostat you most likely have a low voltage one which would be used to control a central furnace boiler or something similar. Double pole thermostats have an off setting and break both sides of the heaters power line. Its rated for a higher current.
If there are four wires you have a double pole. This allows for the thermostat to operate on two separate circuits. Double pole wiring apart from the fact that it accepts two pairs of hot wires a double pole switch is different from a single pole one in another important way. The rating is marked on the switch and it must be the same as or preferably higher than the current draw for the device it controls. Double pole thermostats can be turned off so no matter how cold the room gets they will not turn the heater on. If you see two wires coming out of it in the back you have a single pole.
They typically have four 4 connection wires. Using a wire connector connect the hot supply wire to the thermostat wires. Connect the remaining thermostat wire typically marked t1 or load to the same color supply wire feeding the baseboard heater. Hence a single pole thermostat never turns the electric heater off by cutting power supply line from the heater.