Heater is not blowing hot air. Just recently replaced T-stat and water pump. Any ideas why it would not be getting hot air into the interior. The heater inlet hose is hot at the firewall, so I would assume that the hot water/coolant is getting to the heater/ac assembly, but maybe not. Any help would be greatly appreciated.

 

Have you checked the outlet side of the heater hose at the firewall to see if it is also hot? If not, signs of a clogged heater core. If it is hot, you have a air vent damper issue where it is not redirecting the inlet air from the A/C coil to the heater core.

 

Well today I pulled the heater inlet hose off and the outlet hose at the water pump and flushed it. Some nasty looking stuff came out and let it run through for a little bit. I hooked everything back up and checked it and I had heat again. I don't understand why when I replaced the water pump I flushed the system it would have clogged up my heater core, but oh well it works now. Thanks for your reply.

 

That crud could have been there for quite a well. Slow build up over time. Do you flush often? I flush mine every winter whether it needs it or not just to maintain fresh clean coolant.

 

Well I guess it's not working again. I guess I'll have to flush again and see what happens. We bought it used so I have no idea how often it has been flushed. I'll try again and see what happens.

 

Check your radiator, you're on the right track. The radiator could be deteriotating which may have caused your initial water pump and stat failure because of debris coming off the radiator.

 

Also, when you finally get your heater core flowing really good, go and buy a heater hose coupling. You can get one from NAPA auto parts for a couple of bucks. This coupling will be used to connect both the inlet and outlet hoses together to bypass the heater core during your radiator flush so you won't get any contaminates back into your heater core and plug it up again.

When flushing out or unclogging your core, make sure you flow water or cleaning solution in the opposite path of the antifreeze flow so you won't make matters worse. Basically connect your waterhose to the outlet side of the core.

Once you have confirmed that your antifreeze mixture is clean and your radiator checks out, remove the coupling and reconnect the hoses back to the heater core.

Right now, I can tell you that heater cores are not cheap for the Durango. Cheapest core aftermarket is around $100 with a 1yr warranty. Dealer part runs about $150. Dealer is the best place to go as they offer a 3/36k warranty on the core. Make sure you actually open the box and inspect the core before you walk out of the parts department. I found alot of the cores are either rusted, appear used, cheap plastic parts instead of 100 percent metal, etc.. Only the dealer has 100 percent metalic assemblies.

Let the dealership replace the core for you unless you really know a reputable friend that knows how to replace the core. This procedure will require a complete takedown of the dash and steering column assembly. Dealer usually charges around $400-$500 to do this as this is a very easy 8 hour or all day job.