🔍 Key Concepts

• Boiler combustion behavior when water is mixed with fuel oil • Purpose of a settling (settler) tank and the difference between high and low suctions • Effects of changing fuel pump speed and air supply pressure when the problem is contamination, not demand

💭 Think About

• Ask yourself: does sputtering from water in the fuel mean you need more fuel/air, or that you must improve fuel quality? • Which system component is specifically designed to help separate water and sludge from fuel before it reaches the burners? • Which options would actually risk worsening flame instability or carryover of water instead of removing the cause?

✅ Before You Answer

• Identify which choice directly addresses removing water from the fuel supply, not just masking symptoms at the burner. • Consider how using high vs. low suction on a settling tank affects the amount of water and sludge taken into the service system. • Confirm which actions (pump speed, air pressure) simply change firing rate/combustion conditions but do nothing to separate water from the fuel.