Coleman electric heater doesn't cycle

[Oldtimer48]

Hello. My Coleman electric heater doesn't cycle on and off sometimes. I have it set at 66* at night and in the morning it's 57* in the home. I shut the thermostat off then back on and it starts and cycles on/off all day long like it should. The stat is new. Just two wires. No AC.
Thanks

[KianDicki]

The cause of this problem may be that the temperature sensor is incorrect or damaged.