Result Kangoo ZE33... HVAC fault! it runs on when parking up..

it's been happening for ages. generally in moderate temperature.
close the door. lock up. the heating and ventilation kicks in. Sometimes running for a moment or to and other times up to 10 minutes....??

I have put it in to Parks Renault at Dunfermline. I will update you with the outcome. or cause and what's done to repair it👍