Fan coming on frequently for HP Slimline 270P024D

[CuriousDY]

Hello.  I helped my dad replace the 1 TB hard drive that came with his HP Slimline 270P024D with a WD Blue SSD.  The drive works well, but I noticed that the fan was coming on frequently.  When I returned the computer to my dad, he noticed that the fan was turning on with few programs open.  The computer wasn't blocked up with dust.  I had to remove the heat sink and fan in order to replace the hard drive and I'm wondering if removing the heat sink and fan made the thermal paste less effective.  The computer is about 1 1/2 years old.  I cloned the boot drive and no further programs were installed prior to replacing the hard drive.  I installed a CPU temperature monitor program which showed that the processor ran about 31C when I left the computer alone and when I opened programs, the temperature would jump to 50C-54C.  After opening the programs, the temperature would hover in the mid 40's.  Would cleaning off the old paste and placing new paste help this fan issue?  Thanks.

[ctrl_alt_del]

It is mandatory to replace the thermal paste after removing the heatsink. Replace the thermal paste with high quality thermal paste like Arctic Silver 5, or Noctua NT-H1, after cleaning the old thermal paste. Another problem might be insufficient airflow to clear all of the hot air out of the case. Try opening the side panel and see if the heat problem goes away.

[CuriousDY]

Thank you.  I will try this solution.