99 montana NO HEAT

I am getting no heat ...99 Montana. t-stat changed ..cooling system flushed.getting up to proper temperture..but no heat in pass.compartment....do I have a malfunctioning accuator door??:banghead:

Does the air flow seem OK when you change the output knob? (For example, defrost, front vents, floor)? I had the actuator door right under the passenger side dash go bad on mine, but all it did was prevent it from redirecting the airflow per the knob indicator. I had all floor heat, all the time!

There is no heat at any setting, just cold air. Thermostat was changed and cooling system flushed and still no heat. Temperature runs between quarter and half.

I have the same problem! Changed thermostat and flushed cooling system and still NO HEAT in any position. Any idea what this could be causing this???

All fixed now - lots of heat!! Took to qualified rad shop and had heater core flushed separately... Had previously taken to cheap quick lube shop to have cooling system flushed but it turns out that their claim of being able to thoroughly flush a cooling system is completely false.

All fixed now - lots of heat!! Took to qualified rad shop and had heater core flushed separately... Had previously taken to cheap quick lube shop to have cooling system flushed but it turns out that their claim of being able to thoroughly flush a cooling system is completely false.:bananasmi

Had the exact same problem, turned out to be an air pocket in the heater core. Flush the core was the cure.

Then I noticed a intake gasket leak... :( Bummer

do not put a t-stat made in mexico as they will not open get one made in usa and it will open 180 or 190