Why does the Wrangler not blow hot air after switching to heating mode?

[AmeliaLynn]

Wrangler not blowing hot air after switching to heating mode may be caused by the following reasons: Thermostat stuck open or opening too early: This causes the cooling system to enter major circulation prematurely. When the external temperature is very low, especially while driving, the cold air quickly cools the antifreeze, preventing the engine water temperature from rising and resulting in no hot air from the heating system. Water pump impeller damage or slippage: This leads to insufficient flow through the heater core, preventing heat transfer. Air lock in engine cooling system: Air locks cause poor circulation in the cooling system, resulting in high water temperature but no heat from the heater. If there's constant air in the cooling system, it's likely due to a damaged cylinder head gasket allowing combustion gases into the cooling system. If the inlet pipe of the heater core is hot while the outlet pipe remains cool, this indicates a clogged heater core that needs replacement.