Bob and Tim are at a customer’s house that has a gas furnace and electric air conditioning. The complaint is that the system is not working at all. They talked with the customer, who said, “Everything was running fine yesterday. We noticed late yesterday afternoon that the house was beginning to warm up. Since it is not very hot, it was not very noticeable. But, this morning we got up, and we noticed it was very warm and humid in the house.”
“We will go see what we can find,” Bob said. “Surely we can fix this in a very short period of time.”