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Q: My air conditioner works great but the Heat doesn't air blows out warm at first but then cools down after a couple minutes

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I have barley have any heat. It starts out warm then within couple min it cools down. Air.conditioning works great. I've had the thermostat and sensor replaced and nothing. Any idea why this would b happening?
My car has an automatic transmission.

Hi there. The lack of heat could be, the heater core is restricted. A cooling system flush could return proper flow through the heater core. A faulty heater control valve could also prevent proper flow through the heater core.There is the possibility, the temperature blend door actuator is faulty not fully changing the blend door in the HVAC (heating, ventilation, air conditioning) distribution housing. I recommend having your vehicle’s heater doesn’t work properly be diagnosed and repaired by a certified technician, such as one from YourMechanic.

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