Hi

my 2006 Roomster doesn’t seem to have any heat or cold ac, the ac light is on but the blower just blows the same temperature whatever hot or cold setting you choose

Just wondering where to start to find the fault, could it be the hot to cold knob ? Do I need to buy a scan tool to scan codes and if so what type ?

any advice much appreciated before I start looking 

Is it manual temperature control (a knob you turn), or electric (climate control)

 

Could be broken flap in the duct which blends the cold air and hot air which passes over a heating surface, (or the link cable broken or detached, or the motor failed or jammed if electric), if electric could be temperature sensor.

 

If never gets hot then might be failed heater matrix, or leak on pipes that supply it.

It has a knob that you turn hot to cold, nothing changes just stays the same outside air temperature whatever setting with or without ac light on 

stupid question, do the positions change, windscreen, footwell etc ?

 

I'm thinking possibly the unit itself not working. I have a spare one.