Help with 2006 vvti climate control issues

[Paul B73]

Hello all,

I have a strange fault with the climate control on my Avensis 2006. It has the standard dual climate control. It seems to be blowing hot air all of the time even when I set it to auto (with ac on) & 19 degrees. It will only blow out cold when I change it to 'Lo', then it blows very cold air out.

So for all temp ranges from 17 degrees to 28 it just blows hot. 

I have bought a replacement control unit off eBay & fitted that - still having the same issues.

Does anyone have any ideas (apart from ECU.....)????

Thanks in advance.