Think I may have found a reason why my newly purchased L322 2004 Vogue 4.4 petrol was so cheap 🙂
Came to put the aircon on driving home and all that would come out was warm air. Not just ambient warm, heated warm. No matter where I set the temperature controls.
Anyone have any ideas where I should start investigations?

An AC gas leak

If that was the case, wouldn’t I expect the air to be just at ambient temperature, not heated up?

Has it got LPG fitted?
I used to have a BMW 540 and the LPG vapouriser had been plumbed incorrectly causing constant hot air

Nope. No LPG. 100% standard

As Mikey says I'd check the air con is gassed. If thats OK and holding the pressure I would suspect the compressor is stuffed. If you can check the live values and fault codes that would confirm. Also try selecting the max air con button if that doesn't make any difference at all then that's your most likely cause. When my compressor died the fatty was blowing very warm all the time no matter what setting just like yours and got so bad we were driving with the windows open just to get some cool air in. Trip to the garage me thinks

Most likely cause is this I had it on mine drivers side was all ways hot

https://rover.ebay.com/rover/0/0/0?mpre=ht...2356783074

I was wondering if it might be that valve.
Did you change it yourself, or did a garage do it? Any idea if its an easy DIY job? I assume the calling system has to be drained down to do it?

Oddly the HVAC started working again bit after this. Now the car is sold so I never did get to the bottom of this.