Hi everyone. We have a 68 plate MP which has a very loud whirring type of noise coming from the compartment next to where the gas bottle goes. Could be a fan or something that won't switch off but never heard it before. It has been 36 hours now since it started and is audible from outside the van. I've booked it in to Mercedes Newcastle but quickest appointment is a week tomorrow. Any ideas and also maybe how to stop it please?