Thermoking md-200 shuts off to code 18, its full of coolant water/antifreeze mix. Runs for 10 minutes and shuts off it squirts some coolant out of the reservoir overflow tube that dumps between the truck cab and the box. The engine is smoking hot and the coolant looks full at the radiator cap but I can stick a finger in and it's just above body temp while the controller says the engine temp is 220degrees.

The coolant temp sensor is new, I removed the thermostat, the suction pressure is set to 17psi and the unit runs fine on electric. I'm wondering if the water pump is the problem or if something else?