2000 silverado heater

[Mberry72]

Hello, new member with a heater problem, first I had to remove quick connects on heater core lines, they where cracked, second I flushed and changed fluid because had over 180 k miles, that winter noticed heater not as hot, so I changed thermostat, didn't do anything, so flushed heater core and flow was real good. Still no dice. So bled system and really no change, no leaks on hoses or pump and truck has not overheated every since I have been having this issue, does anyone have a idea, what it could be

[Daryl LBZ]

*Moved to correct section*

[rjgti]

did you back flush the heater core

[BLACK DEATH]

As posted above flush heater core, that's what I do to fix this issue