No heat?

Check the blend air door. It is located near the heater core. If it is stuck, then you won't get heat

Hello,
I saw your other posts before seeing this one, so I've responded several times.

The blend door actuator on the drivers side (closest tot he floor) is most likely the one which controls the heater door. Remove the actuator and turn the rod by hand. with the engine running and at normal temperature you should then feel heat. Try this several times to be sure its the proper one. if so then repalce the actuator.

Read my posts at the very bottom of the page at this link to the Chevrolet forums. In particular this has to do with the Uplander. https://chevroletforum.com/forum/uplander-31/2008-uplander-heat-problem-20931/page10/#post486041

Try this again. Read my posts at the bottom of this page if you have an Uplander with no heat at idle. https://chevroletforum.com/forum/uplander-31/2008-uplander-heat-problem-20931/page10/#post486041