Chevy & GMC Vans

has anyone replaced a heater control valve yet ? My 2002 Astro doesn't get hot ?any ideas ? Radiator is full and water pump and Intake Gasket are brand new.

Question:
with the engine running: If you move the selector from 'COLD (blue)', to , 'hot (red)', can you actually hear the vacuum actuated door that directs the air, can you hear it move at all?
Reason for question: If the heater is heating, but the door isnt opening to allow the heat to get to the outlets, you will need to fix the vacuum leak that keeps your heater control from operating.

You can check the 2 heater hoses that go into the box on the firewall on the passenger side. Theses 2 coolant hoses go to the heater core. If they are hot when selected for heat then the issue is not the control valve. There is a thread here someplace where one of the members replaced his control valve.

Thank you for the tips and comments

Great looking van! I love it!

She's a 2002 Explorer Limited edition AWD High Top. Explorer Vans has been fantastic about factory replacement parts -122k miles on the clock.

I hope you don't mind if I piggy back your thread; my questions are along the same lines.

I've got a 98 Safari. As it's been getting colder I've noticed that the heat/defrost gets warm but not really hot. I believe that the heater control valve is working fine, the engine just doesn't get that hot. The thermostat in the dash get a little above 100 but not much. Normally a cool running engine is a good thing. Is there something available that partially obstructs the radiator and could raise the temp a few degrees?

I would see about replacing the thermostat. These 4.3's generate lots of heat so you most likely have a stuck open thermostat. What I used to do with my old cars was place a piece of cardboard in front of part of the radiator.

The heater hose fitting coming from the intake manifold is restricted down to a tiny opening and buying one with a larger hole or drilling out yours lets more hot water get to the heater instead of going directly to the engine radiator.