Ok, so I drained the radiator and engine block in order to replace the water pump. The water pump replacement went fine but now I've added the new coolant (Zerez G0-5) the temperature gauge reads 100+. It used to read around 87 on a hot day before. I tried burping the system using a funnel by setting the heat to high (I have the latter climate control system) and the heat system to vent. I also raised the front of the car. The thermostat is a couple of years old, it's a 79 degree one that I checked was working before I put it back in. The top radiator hose gets hot so I know the thermostat is opening. There's little heat coming out of the defrost vents. I'm flummoxed as to why this is happening, is there some trick I'm missing?