This service was longer than usual as when it was due the temperature was -40. The heater would not function but the engine started easily. Rather than risk driving with no heat and not needing the car I waited until the outside temperature was over zero. The car again started easily and the heater was also working. All I did was top up the antifreeze. I reported the malfunction and this was checked as part of the service. Like me the service could not find any reason for the malfunction. Next winter I will make sure the antifreeze is topped off.