Thermostat / Heater problem?

while working on my Durango, I replaced the thermostat, and YES its installed correctly… but I can’t get any heat into the cab.

The upper radiator hose is nice and hot, any suggestions?

Bleed that air out of the cooling system.

You don’t mention the year of this Durango. If both heater hoses are fairly cool and don’t heat up quickly, you might have an air locked or a clogged heater core. Remove both heater hoses at the engine and flush with the garden hose through one hose and then the other. On the final flush lift both hoses high so all air is flushed out the heater core. With the hoses still elevated, clamp off the hoses near the engine end. Attach the hoses to the engine, refill the system, and remove the clamps.

With the engine running see if both hoses get warm quickly. If you still have no heat you have a HVAC problem with the air handler under the dash.

That should cure your problem.

Thanks.
Whats the best way to do that, break the seal on the upper hose?

To quickly purge any air out of the cooling system, get the engine up to operating temperature. With the engine idling, slightly loosen the upper radiator hose clamp. Take a flat bladded screwdriver and slip it between the radiator hose and the hose neck on the radiator. Allow the engine to idle until all that comes out is coolant. Retighten the hose clamp and check the coolant level.

Tester