All,

Thought I would add to the collective knowledge shared in this forum by sharing an issue I was having and the fix,
I started noticing that my heater would go cold while driving (usually when at a traffic light). Along with that, I had started noticing over the last month or two my Engine temp gauge starting to trend up (though not spiking). Thought this was two separate issues but turned out to be a leak in the water pump.
Issue: Low coolant/water mixture not being passed to the heating core (which acts like a radiator).
Fix: New water pump, sensor and coolant.
Result: Engine temp indicator now is just below mid-line when warm which is usual behavior and heater works as expected.
In retrospect, I did notice some pools of water under my car over the last few weeks but was not sure what that was. Obviously that was the leak.
Cost: Around $400 at a reputable shop