Block heater observations

[Piotrsko]

On the ERanger, I have a homemade 3kw coolant heater plumbed to the heater box and pumped with a rather expensive 12v brass piersberg centrifical pump that comes on after the batteries are charged. I need the centrifical pump because it allows fluid bypass without much pressure loss, but chinese plastic pumps don't hold up at the pressures and temps used. I control the temps with aftermarket water heater controllers