Heat

[Fetch]

I really appreciate the help. What if it still doesn't get very hot after adding coolant? What do you think the problem could be?

Some other things that come to my mind,
Heater Valves
Aux Pump
Clogged heater core/other coolant line

Try searching for heater valves, and then aux pump and see if any of that is useful to you.

It could possibly be the heater valves not opening, however, I forget if when they break they stay stuck open or closed, so I could be wrong on that.