why does my Volkswagen Passat B8 (2015-2022) AC only blow hot air

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to avoid electrical shorts.

2. Recharge Refrigerant

• Tools Required: Manifold gauge set, refrigerant (R-134a), safety goggles, gloves.
• Connect the manifold gauges to the high and low-pressure ports of the A/C system.
• Open the valve on the low-pressure side and observe the pressure readings.
• If low, add refrigerant according to the manufacturer's specifications (typically around 2.1 lbs for the Passat B8).
• Monitor the pressure during charging to avoid overfilling.

3. Replace A/C Compressor (if necessary)

• Tools Required: Socket set, wrench set, A/C compressor removal tool, torque wrench.
• Locate the A/C compressor on the engine.
• Disconnect the electrical connector and any refrigerant lines (ensure system is fully evacuated).
• Remove the mounting bolts securing the compressor.
• Install the new compressor, ensuring all seals are replaced to prevent leaks.
• Reconnect refrigerant lines and electrical connectors.

4. Replace Cabin Air Filter (if necessary)

• Tools Required: Screwdriver set.
• Open the glove compartment and remove the stops to access the cabin air filter compartment.
• Take out the old filter and inspect for debris or clogs.
• Install the new filter, ensuring proper orientation according to airflow direction.

5. Recheck System Functionality

• Reconnect the battery and start the vehicle.
• Set the A/C system to the coldest setting and verify the compressor engages.
• Monitor cabin temperature for cooling effectiveness.