Regardless of their size and type, boilers can be dangerous, causing loss of life and significant property damage, if not inspected and maintained properly.

While there are safety devices to prevent dangerous boiler operating conditions from turning into disasters, only proper maintenance can prevent dangerous boiler operating conditions from occurring. The only way one can be confident control or safety devices are functioning properly is to perform required maintenance, testing, and inspection regularly.

Regular inspection of boilers is the law--most often, governed by states, but in some cases, governed by municipalities and cities. Boilers must be examined by certified inspectors according to a mandated schedule. The day-to-day maintenance and servicing of boilers is the responsibility of building engineers, plant- and facility-maintenance managers, and/or building managers. It is important to note that most problems do not occur suddenly; instead, they develop slowly over a long period of time--so slowly, in fact, they often go unnoticed by maintenance personnel.

In addition to safety, regular boiler inspections are important to optimal function and energy efficiency. Boilers are high energy users--typically, second only to air-conditioning systems in annual energy use. Inefficient operation means wasted energy and increased costs.

Regular inspections also can extend the life of a boiler.

Inspection laws getting stricter. Boiler-inspection laws are getting stricter nationwide. For example, New York City now requires owners of low-pressure boilers to have a licensed boiler-repair contractor correct defects found during an inspection and provide written confirmation of the corrections within 45 days. A boiler then must be re-examined by an approved inspector to verify the defects have been corrected. Once the re-inspection is complete, the owner must submit an affirmation of correction signed by the approved inspector attesting to the compliance of the boiler. Failure to comply with these requirements can mean fines of up to $1,000 per boiler per year. Previously, there essentially was no penalty for failure to correct deficiencies; there only were penalties for not having an inspection.

Overdue inspections mounting nationwide. The problem of overdue boiler inspections is fairly widespread and growing. For example, during fall 2008, it was reported that Washington, D.C.'s Department of Consumer and Regulatory Affairs (DCRA) had failed to inspect and certify thousands of boilers in District buildings and that the District fire department had responded to 119 boiler incidents during the previous two years.

The DCRA, which was understaffed, had certified as safe some commercial boilers with problems cited by insurance inspectors, such as leaking relief valves, significant mineral buildup, and inoperative safety valves.

The commercial-inspections section of the DCRA performs its boiler work through in-person examinations or the certification of insurance-company inspections. With a shortage of boiler inspectors, the agency focused on schools, firehouses, police stations, and libraries, leaving many commercial boilers unchecked and private inspections unverified.

KEY BOILER-SAFETY FEATURES

Boilers have a variety of features designed to prevent accidents and keep them functioning at optimal efficiency:

• Safety valves. Safety valves are the primary safety feature on a boiler. Safety valves are designed to relieve all of the pressure generated within a boiler if other systems fail. Every steam and hot-water heating boiler must have at least one safety or safety relief valve of sufficient relieving capacity to meet or exceed maximum burner output.

The ability of a safety valve to perform its intended function can be affected by several factors, including internal corrosion and restricted flow.

Internal corrosion typically is the most common cause of "freezing" or binding of safety relief valves. This generally is caused by slight leaking or "simmering" attributed to improper seating of a valve disk and is a condition that must be corrected immediately. A boiler never should be operated too close to a valve setting because the set pressure will cause the valve to leak slightly, resulting in internal corrosion buildup that eventually will prevent the valve from operating.

• Water-level control and low-water fuel cutoff. These two devices perform two separate functions, but sometimes are combined into one unit. It is important to ensure piping is open and free of scale or sludge buildup at all times. Cross tees allow piping to be cleaned and inspected easily. Low-water fuel cutoffs should be checked periodically for proper operation. Because this requires boiler water to be lowered to the minimum safe operating level, extreme caution should be used.

In addition to periodic tests of a low-water device, the float chamber on a water-level control and/or a low-water fuel cutoff should be flushed thoroughly to remove accumulated sediment. At least once a year, water-level controls and low-water fuel-cutoff devices should be disassembled, cleaned, and checked.

• Water gauge glass. A water gauge glass enables an operator to observe and verify the actual level of water in a steam boiler. If not properly cleaned and maintained, a gauge glass can appear to show a sufficient level of water when a boiler actually is operating in a low-water condition. A stain or coating sometimes develops on the inside of a gauge glass, where the gauge glass is in contact with boiling water. This stain can give the appearance of water in the boiler, especially when the gauge glass is completely full or empty of water.

If necessary, replace a gauge glass, even if the boiler must be shut down. That inconvenience is nothing compared with the damage that can result from a boiler being operated without a functioning gauge glass. The connection lines to a gauge glass can become clogged and show normal water levels when water is low; thus, the piping connecting a gauge glass to a boiler should be cleaned and inspected regularly to ensure it is clear.

A boiler's fuel system, particularly the burner, requires periodic cleaning and routine maintenance. Failure to maintain equipment in good working order can result in high fuel costs, the loss of heat transfer, or a boiler explosion.

Boiler logs may be the best method of ensuring boilers are maintained properly. Because a boiler's operating conditions change slowly over time, a log is the best way to detect significant changes that otherwise may go unnoticed. Maintenance and testing should be performed and recorded in a log on a regular basis.

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