The first cold weather of fall has prompted a service call to a residence because all the windows in the house were sweating on the inside. The customer explained that all seemed well with the heating system until the windows began to sweat and he wanted to know if the heating system could have anything to do with the problem.
Bob arrives and talks to the homeowner who tells Bob that he just wants to make sure the heating system is working properly. For some reason the windows began to sweat when the weather became cold. It all seems to relate to turning on the heating system.