___ combustion is combustion that occurs when all fuel is not burned.

The purpose of the National Electrical Code® (NEC®) is the practical safeguarding of persons and property from hazards arising from the use of electricity.

All returns from a fuel oil heater should be properly dumped to eliminate the possibility of further contamination.

All returns from a fuel oil heater should be properly dumped to eliminate the possibility of further contamination.

Steam loses heat at the point of use.

The operating range of a boiler is controlled by a(n) ___.

According to incident reports from The National Board of Boiler and Pressure Vessel Inspectors, the most frequent causes of boiler incidents are operator error and poor maintenance.

Heavy fuel oils are relatively easy to pump and atomize for burning.

After a boiler is dumped, it should dry completely before cleaning.

The operating range of a boiler is controlled by a(n) ___.