Bob gets a call from the dispatcher that a residential customer out in the country has an oil furnace that has to be reset to get it to run. Bob tells the dispatcher to call the customer back and tell them not to reset the furnace again until he gets there. He will be there in about an hour.
It is very cold so Bob gets there as soon as possible. When he arrives, the customer shows him where the furnace is located down in the basement. It is off because of safety again. Bob knows to check the furnace for excess oil before he resets the primary control. He uses his flashlight and examines the combustion chamber. The furnace is not hot, so he rolls up his sleeve and puts his hand into the combustion chamber and discovers that it is dry. He knows not to start up a furnace that has oil standing in the combustion chamber. His examination with the flashlight shows a lot of soot in the area of the combustion chamber and heat exchanger.