Dodge Repair: Caravan 07 3.3 L: no heat after maintaining system


Question
i have a dodge caravan 2007 with 3.3 liter engine,i just change the thermostat and radiator cap but i don't have any heat at all coming out inside the van,heather fan is working but all i have is cold air.

is there a valve on the line somewhere or something else that i could check to fix this probleme

Answer
Hi Luc,
How hot are the two hoses that go from the engine compartment into the cabin where the heater is located? They should be about equally hot. If not, then either there is an air bubble in that heater core line that is preventing cool flow,  or the heater core is partially blocked.
Chances are it is air trapped in the system. What you need to do is drive car as usual for a few days and you will likely notice that the coolant level in the recovery bottle is dropping as the air bubble is replaced by coolant. So keep adding coolant until no longer does it keep dropping. At that point there should be much better flow through the heater core and you will get heat.
After that trial period, if the two hoses are still not about equally hot then you might have some crud to flush out of the heater core.  Were that the case you would want to remove the hoses, after draining down some of the coolant to avoid losses, and then flush the core using a garden hose. Do that in both directions so as to loosen up any crud in the 'loop'.
Then refill and go through the several trips while adding more coolant to replace the trapped air.
Roland