block heater

I’m wondering if the 2021 F-150’s block heaters only close the circuit below a certain temperature? It doesn’t matter much as I usually don’t plug in until -15°C, but my coworkers have been talking about other brands that use a thermostat to activate the heater.

Has anyone in Canada or anywhere that has a 2021 F-150 for the winter in your area, ever remotely started your truck while your truck's block heater is still plugged in? Any issues or better to remove it than start? I had a friend ask me this question as we are dropping down to -40 with WC...