Climate Control not working on Low heat

Do you hear the blower motor running at low settings? Listen at the base of the windshield (outside). That is where you should be able to hear it the best.

Yes the motor works fine, as when I put the settings on Auto and say the temp is on 29 C, the front went are throwing air, which is neither hot or cold, but there is no heated air coming out. When I raise the temp to 32C it is full hot air blown.

Sounds like maybe a sticky air mix door. Keep in mind that the programmer decides where to distribute the air (at least on mine it does). Heat gets delivered to the bottom (foot vents) and A/C or ambient cooling gets delivered to the vents. If there is a vacuum leak, it will default to defrost.

Today it was bit cold here. Around 6* Cent here. It was dark so the Sun Sensor was also not thinking the car to be in hot spot. I kept the setting on 24* Cent and believe me it was getting cold air from the front Vents. I raised the Temp to 29* Cent and there was hot air for some time and then again Cold Air. What I suspect is that there are some Sensors, which are not working properly or something like that. Can anyone advice.
Thanks,
Reco.

There should be a small 1" square grill to one side of the steering column. That is the intake for the asperator. That is where cabin air is sampled to tell the ACM if the cabin is at or near requested tempurature. There should be about a 1" tube behind that grill with a sensor in line someplace and I think a small fan to draw the air. Make sure all that stuff is connected properly.

Today it was cold here and I was on the highway. Here is what I noticed. The Temp outside was 6* cent, and I put the control on 24*C. I heated the inside upto like 15 minutes and then cool air started coming from the front vents, I raised the controls to 26*C and after that it was warm air, which came from the vents throught out the length of my drive.
What looks like is that the there is some sensor setting which has raised the temprature. Looks like at 24*C, the sensor thinks that the car is hot and would raise the cooling but at 26*C settings it behaves as the car is cold and would continue maintaining a comfortable temperature. Also, please note that this was during the night, so bright Sun had no role to play in this.
Thanks