During the course of a home inspection I remind clients that in order for appliances to operate safely and efficiently, they should be maintained on a regular schedule as recommended by the manufacturer. In the photos above you will see a water heater that I came across at a home inspection. Clearly there are some combustion issues. This is evident by the flame blow out at the main burner at the bottom of the unit, as well as the soot blow back at the upper vent stack. This home was vacant and the gas was shut off so I could not check to see if the flame was proper and if the unit was venting properly. Flames blowing out of the bottom of the water heater could result in ignition of combustible materials close to the water heater. The back draft at the vent stack would be releasing Carbon Monoxide into the room. I recommended service prior to operation to ensure that the unit operates properly.