why is my savana overheating?

What is your question?

I replaced a noisy pump &t-stat, also radiator, due to small leaks @ bottom of sides. Now van is overheating and am not getting any heat,top hose hot bottom hose cool. Originally van was not overheating,got good heat,just loud noise from pump,never had leaks either, I am stumped.

What makes this problem better or worse?

overheats while idling or short trip down road

How long has your 2006 GMC Savana 3500 had this problem?

a few days since i changed pump,stat,rad.,