[RBRIEL]

No heat from any mode
Heater control vale appears to be working
hoses are hot on both sides when temp control is turned to 90 deg

does the heat/cool diverter in dash control both sides since it has dual temp control

I can see the diverter open and close on passenger side when i change temp setting but still no heat

 

[lisantica]

My 2011 Armada had a similar issue. I followed the instructions in this video and I now have heat.

Another video I found:

This comment is what worked for me too:
"I would find a spacer that would butt up against the cover and keep pressure on that gear. stacking small washers would work as a shim as well."

 

[crazy4trains]

OP says heater control valve appears to be working. If that is truly the cast then the above videos won't help.

I would check, then check again to verify proper operation of the heater control valve as it is the most likely culprit.

After some time even the stopgap repairs mentioned in the videos quit working for me. A new Gates heater control valve solved the problem.