Help with boiling coolant. 06' Chrysler 300 base.

Hello,

'06 Chrysler 300 base model with 118,000 mi.

About 1.5 mths ago I had the gaskets replaced due to slight burning smell,
they had never been replaced prior. Two weeks ago, when out driving,
turning the car off on every 15-30 mins and driving, to stop again (sales visits)  
I heard a rumbling under the engine with idling, A/C was on and cooling. I
popped my hood and noticed that the radiator fan was somewhat out of
place, causing it to not take its usual circular path. The car's temp gaguge
nearly reached 1/4 up so I turned it off and let it cool, driving to the mechanic
with no overheating on the way,. They said the fan needed to be replaced as
it didn't power on, it was never replaced prior. I changed the fan myself, it
turns on/off as needed but the coolant continues to boil, without the car
overheating..

I've been reading some online, but not all scenarios are unique.
Could the gasket replacement have something to do with the boiling?
I have found no coolant leaking from anywhere, on the street at least, as I
have no means of lifting the car.

Water pump?

I sincerely appreciate everyone's input and guidance!

thanks!