The context
A customer called us because their system had stopped. Nobody had serviced it for two years, and it had now broken down. We had not installed it, and that does not matter: a heating or cooling system does not care who fitted it, it just needs someone who understands it. Two years without maintenance means nobody has checked the settings, the wear, or the effect of a power cut. When a machine in that state stops, the cause is rarely small.
