2000 Honda Civic Engine Overheating

My issues started about a month ago after I had performed my own coolant change on my car 6 months prior. My radiator in my 2000 civic is about 6 years old btw. When driving about a month ago, I noticed my temp gauge was fluttering from 40% normal operating temp to about 60% to H , after going to the shop they diagnosed a failing water pump and radiator cap was old/failing. Replaced both and put new coolant into the system. Drove the car for a few weeks with no issues, until the other day, I was driving for about 45 minutes with no overheating issues until I was at idle in a drive thru line, I noticed my temp gauge was back up to about 70% to H. I turned my heater on, which blew hot hair into the cabin and lowered the temp a little. I proceeded to drive my car home and I turned off the heater to try to diagnose anything and my car returned to normal operating temp (at least the gauge was normal). I guessed that since my car temp was ok while driving maybe it was a failing fan?  reverse phone lookup  nba reddit

Because you have cabin heat at idle, that indicates there's both flow  from the water pump and at least enough coolant to circulate through the heater core, which is usually hard to do if it's significantly low on coolant. So, I'd look at the cooling fan, and radiator. If this car has A/C, is there a bunch of debris stuck between the condensor and radiator?  does cooling fan run? are  blades to fan intact?  Has the T-stat been inspected or replaced?  verify radiator cap is the correct pressure. If all that checks out, you might have a head gasket issue developing. 

Radiator fan inop. When driving you get plenty of airflow through the rad, keeping it cool. When stopped idling the fan provides the airflow. Figure out why your fan isnt running.

Those Civics can be difficult to bleed the air out of the cooling system.