What Causes the Car Heater Not to Heat Up?

[VonJessica]

Car heater not heating up reasons and solutions are as follows: Reasons why the car heater does not heat up: Blower malfunction leading to air door flap or air door motor failure; Water temperature sensor signal failure; Heater core blockage, requiring disassembly for cleaning or replacement; Water pump slippage or damage, heater flow valve and coolant circulation valve failure; Failure to bleed air after replacing coolant. Solutions for car heater not heating up: Check the operation of the blower at each speed setting, ensuring each setting reaches sufficient RPM; Install or replace a new thermostat; If equipped with a bleed port, bleed air first. If ineffective, manually feel the two heater hoses. If there is a significant temperature difference, flush the heater core or heat exchanger directly with a water or air gun; Check if the filter is dirty or clogged, clean it, and replace if necessary; Bleed air promptly.