I had the thermostat replaced about a year ago. Now, my heater is blowing air that is barely warm. It should be much hotter. Any ideas?

 

Have you scanned the car for DTC codes (error codes)??? If you havn't invested in a VAG-Com, you should.

 

I agree Jest, It would be good to get a VAG, Until then, does anyone have any ideas why the heater would be blowing cool air when the temp gauge reads normal, the thermostat was recently replaced and I have coolant?

 

Several reasons.

Try putting the temperature up to high and see if there is a difference.

some possibilities include
Airlock in heater core. Did you bleed the system after changing the thermostat?
check the hoses to the heater core with the engine warm. See if both hoses to the core are hot. If not hot water is not going to the core. This means either vapor lock, blocked core or bad valve or actuator. If they are both hot, that means that hot water is getting to the core, and the problem may be a stuck flap valve, bad electronics.

Hope this helps

 

Thanks David, I'll check as you suggest.

How do you bleed the system?