Strange heater issue 2009 Eddie Bauer Explorer

[VintageRedTruck]

My 2009 Ford Explorer Eddie Bauer has a strange heater issue. It is not an issue with the door. With the engine off but key turned on I can switch the temperature control from cold to hot and hear the door switch positions. Once the engine warms up if the fan speed is on the lowest setting I can feel warm air coming out of the defrost. If I increase the air speed the first burst of air is warm but it quickly turns cold. I seems as if there is a low flow of coolant circulating through the heater core. The air flow quickly dissipates the heat from the heater core quicker than the coolant flow can reheat it. I don't know if I have a vapor lock or what. that is the only thing I can think. of. Does anyone have any ideas? If it is a vapor lock, how do I clear it to get the coolant flowing again?

 

[Bazz270]

most probably heater bypass valve became stuck or something happens with vacuum supply.
almost no way for some kind of vapor lock without major coolant leaks or components replaced but you always can purge your cooling system following any Youtube instructions.

 

[2010 Eddie Bauer]

My 2009 Ford Explorer Eddie Bauer has a strange heater issue. It is not an issue with the door. With the engine off but key turned on I can switch the temperature control from cold to hot and hear the door switch positions. Once the engine warms up if the fan speed is on the lowest setting I can feel warm air coming out of the defrost. If I increase the air speed the first burst of air is warm but it quickly turns cold. I seems as if there is a low flow of coolant circulating through the heater core. The air flow quickly dissipates the heat from the heater core quicker than the coolant flow can reheat it. I don't know if I have a vapor lock or what. that is the only thing I can think. of. Does anyone have any ideas? If it is a vapor lock, how do I clear it to get the coolant flowing again?

Your heater core is likely partially clogged, hence the restricted flow of coolant. You may try doing both a coolant flush and heater core flush with a dedicated flush chemical.

 

[Blackhawkxx]

As was said, I would check the heater bypass valve first.