This model (at least in the USA version) has an electric control valve. Many cars with simpler 'climate control systems' have a manual cable actuated valve for this.
It is located on the right (passenger side- at least in the US! What side do you drive on?), under the hood, near the firewall. Just follow the heater hoses.
If you cut the power (pull the plug attached to valve pictured below) to the electric valve (sometimes called a "mono-valve"), the default position is wide open, meaning Hot.
I have tested this.
It will still let a lot of hot air through the drefrost vents, even if the system is completely off in this mode.
I suppose it is possible that the valve is 'mechanically' stuck closed, in which case disconnecting the power will not help.
I saw a repair kit marketed somewhere.
Someone here will know.
A new one is like $80 or so.
