Ford Explorer heater only works while driving and blows cold air when idle on Ford Explorer

Some Ford Explorer owners report experiencing issues with their heater, which only works while driving and blows cold air when idle. Common reasons for this problem include low coolant levels, which are essential for transferring heat from the engine to the heater core. Additionally, some owners have found that a clogged heater core can prevent proper heating, as it blocks hot engine coolant from warming the cabin air. Air pockets in the cooling system may also disrupt coolant flow, leading to inconsistent heating, and bleeding the system can help resolve this issue. Furthermore, a malfunctioning thermostat may prevent the engine from reaching the optimal temperature needed for cabin heating. Other potential causes include a bad heater core, an airlocked cooling system, a faulty blend door actuator, a sluggish blower motor, or a malfunctioning thermostat. To address these concerns, it is advisable for owners to check the coolant level, inspect the heater core, bleed the cooling system, and ensure the thermostat is functioning properly. If these steps do not resolve the issue, further diagnosis by a qualified mechanic may be necessary.