Block Heaters 101

[Sri Ram]

What does the block heater heat and to what temp? Also, does it affect fuel filter pre-heater?

 

[PC12Driver]

It's just a 750 watt heating element that is in place of one of the freeze plugs on the right side of the engine (behind the oil filter). It just heats the water in the block. I don't think it's thermostatically controlled, but on my truck it always seems to heat to 100* +/- 5* whether it's plugged in for 2 hours or 8 hours.