DC Boiler Operator study guide
DC Boiler Operator · Work through your exam, one topic at a time.
The DC Boiler Operator credential is a District of Columbia occupational license for people who operate and maintain steam and hot-water heating boilers in buildings such as apartments, schools, hospitals, and commercial facilities. Licensing for this trade sits with the DC Department of Licensing and Consumer Protection (DLCP), which administers professional licensing through its Occupational and Professional Licensing (OPL) arm, publishes the license fee schedule, and hosts the online application and renewal portals. The DC Boiler Operator study guide has 6 sections and about 2,803 words.
01Boiler Principles, Combustion, and Thermodynamics
This domain tests whether you can reason in energy terms: how heat moves into water, how much of the fuel's heat you actually capture, and what the burner needs to release that heat cleanly. Expect calculation items on Btu input and output, evaporation rate, and efficiency, plus conceptual items on heat transfer and combustion.
454 words, about 2 min02Boiler Construction, Fittings, and Appurtenances
This domain checks that you know how firetube and watertube boilers are built, which fittings the code requires, and what each fitting does. Items often ask you to identify a fitting from its function, or to state a code limit on set pressure or location.
512 words, about 3 min03Boiler Operation, Startup, and Shutdown Procedures
This domain tests sequence and judgement: the order of steps for a cold start, a hot restart, paralleling with a header, and a controlled shutdown. Items frequently present a sequence and ask what comes next, or what would happen if a step were skipped.
490 words, about 2 min04Feedwater, Water Treatment, and Blowdown
This domain covers what is in the water, what it does to steel, how chemicals and blowdown control it, and how often you test. Expect questions on scale versus sludge, oxygen pitting, carryover, cycles of concentration, and the correct blowdown procedure.
434 words, about 2 min05Safety Devices, Controls, and Combustion Safeguards
This domain asks how the boiler protects itself: which device acts, in what order, and how you prove it still works. Expect questions on low-water fuel cutoff testing, flame safeguard sequencing, and interlocks that must never be bypassed.
448 words, about 2 min06Inspection, Maintenance, and Recordkeeping
This domain covers preparing a boiler for internal and external inspection, what an inspector looks for, how maintenance is scheduled, and what must be written down. Items often present a condition - pitted tubes, a leaking gasket, an overdue safety valve test - and ask for the correct response.
465 words, about 2 min