2000 5.3L; High engine temp, no heat

Drained the coolant from the radiator, (5.3L V-8, 118K) and refilled. This engine has a surge tank & cap and does not have a cap directly on the radiator. I then started the engine, with the heater on, and let it warm up and all seemed OK. Ran it on the road and the temperature gauge went up to high, no hot air at all out of the heater. Coolant level is at the full cold level. Thinking that I either have an air bound system or for some reason, draining & refilling may have caused the thermostat to stick. No prior problems. I am thinking of starting over, just drain again and refill while the engine is running this time. Any other thoughts?

Drained the coolant from the radiator, (5.3L V-8, 118K) and refilled. This engine has a surge tank & cap and does not have a cap directly on the radiator. I then started the engine, with the heater on, and let it warm up and all seemed OK. Ran it on the road and the temperature gauge went up to high, no hot air at all out of the heater. Coolant level is at the full cold level. Thinking that I either have an air bound system or for some reason, draining & refilling may have caused the thermostat to stick. No prior problems. I am thinking of starting over, just drain again and refill while the engine is running this time. Any other thoughts?

the pressure cap is to be removed. then with the dexcool added to the full hot mark start the cold engine.

continue to add coolant and rev engine to 2,ooorpm every so often to get the air out . when the engine is at the 190 deg f mark put the coolant pressure cap on ..

this is how to get the air out.

Got it thanks. Just redrained and started over. I filled slowley this time, started the engine and idled for a few minutes, then loosely replaced the surge tank cap, and cycled to between 2000 & 3000 RPM, with the heater on, until the engine came up tpo operating temp. I knew it worked at this point because I was now getting heat out of the vents. I then shut the engine off, removed the surge tank cap, re-filled with dexcool (50/50 mix) to @ 1/2" above the the cold fill and repeated the process. I shut the engine off, tightened the cap, and road tested it. All worked well. :)

FYI: This process drained @ 1-1/4 gallons of coolant from the system.

Water pump is toast, not moving the coolant and leaking out of the weap hole.