Improving Boiler Life and Reducing Accidents

With proper operation and careful maintenance, cast iron boilers can give many years of service. However, there is a tendency to forget about the heating plant when the weather becomes warm enough to shut down the boiler. With automatic controls, heating boilers are taken for granted even during the heating season. The full-text article that follows this summary provides more detailed guidelines for spring shutdown and fall-start up. Here are some general tips to improve efficiency and safety and extend the useful life of your boiler.

Use A Boiler As Intended

A cast iron boiler is intended to be used as a heating plant, either for hot water or steam supply. Use in other applications is asking for trouble. Applications such as steam cleaners and baths, humidifying systems, or process supply require the addition of large volumes of make-up water which contains minerals, dissolved solids, and gases (oxygen and some carbon dioxide). These cause the buildup of sludge, scale, or corrosion on the internal surfaces of the sections.

Water Chemistry

Leaks are all too frequent in heating systems that use cast iron boilers. If a sufficient volume of raw water is added, careful attention to water chemistry will help reduce scale and sludge. Sections can overheat due to lack of adequate water flow and heat transfer through the metal. Cracks from overheating can prevent proper operation of a boiler.

Excessive make-up using hard water (high mineral content) is a typical factor in scale and sludge build-up. Softening the water will reduce the mineral content, but can lead to corrosion. Test raw water to determine if water treatment is required. Antifreeze can help if freezing is a concern but can cause seals to deteriorate between sections. Consult a heating professional before adding products to boiler water.

Maintain Safety Devices

A boiler can become overheated and over-pressurized by a combined failure of the burner controls and an inoperative safety/relief valve. Steam pressure in a cast iron boiler can have destructive, explosive power. Be sure your qualified boiler service company or insurance inspector periodically checks your safety/relief valves.

Burner controls that do not shut off fuel flow can cause similar failures by overheating the boiler sections. Low water cutouts and gage glasses should not be allowed to become fouled by sludge build-up. As part of routine maintenance, these devices should be periodically inspected, cleaned, and flushed out.

Boiler Service Is Key