VCDS/HVAC/Left Temp Flap- Question

Heater air is not very warm. Does not matter if it's directed to dash vents, floor, or defrost.
Heater core was replaced by the dealer when the fix was done a year ago.
Temp of coolant pipes into and out of core are too hot to touch.


So I went to VCDS and checked 08-Auto HVAC, Measuring Blocks/Basic Settings. There are no codes present for any system including HVAC.



I found a Left Temperature Flap - Group 12


I think I understand the values:
Current Value is the feedback position of the motor = 231
Specified Value is the human controlled temp knob on the dash = 231
Cold Stop is the motor position with flap moved for cold air = 32

Warm Stop is the motor flap position for warm(hot) air from the core = 231



My question is this:
When I move the knob on the dash the Specified value goes from the 32 all the way cold to 231 in the middle of the range and then when turned all the way hot it does not change from 231.


Does this all sound like it's working OK? Why does the Specified value not change from the mid position to the hot position?


I'm trying to figure out if the heater core is clogged again or the blend motor flap is not working correctly.


At this point I would suspect that the potentiometer in the motor is reading fully hot when in fact the flap is in the middle position?


Any ideas?

OK - I found that the heater core is clogged with rust. I have a new core and all parts to replace.

But I'm having a problem pulling the aluminum coolant tubes into the heater core connections and getting the clamps on. I can pull them together but then I have to let go to install the clamps.
Is there some better way?

The solution to getting the clamps onto the 'flare' fitting of the core and the aluminum heater tubes are to use longer M4 screws in the clamps.
The OEM screws, when just started in the clamps, cause the clamp to be too tight. If the clamps is not already perfectly aligned and the connection tight, it will not work.
But with longer screws it gives you much more leeway in getting the connection together.

I used a Nissens 70228 heater core. It measures exactly the same dimensions as the original. Including the pipe connections. Today the hot air from the heater was so hot it could burn your hand. And that's what the original heater core was like before it got clogged with rust debris.
And the rust debris is a mystery where that is coming from. I have changed the coolant in this car from time to time just to avoid this type of issue. When the fix was done and core changed I paid VW extra to flush the system and try to get this debris out.