Boiler Water Quality Recommendations

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A boiler is a furnace that transfers heat via hot water (or other liquids) or through steam. The heat transfer can warm homes and provide hot water. Treating your boiler's water will minimize problems and maximize its efficiency.

Household Boilers

A boiler is unique in supplying two household necessities: hot water and warm air. As a result, there is no need for a separate water heater. The drawback, however, is that if the boiler needs repair, you lose both heating and hot water in your home. A boiler can be designed to use a number of sources for its fuel supply. Coal, oil, wood and natural gas create the combustion necessary for power. Electricity powers heating elements in electric steam boilers.

Hydronic boilers are the most common boilers used for residential and industrial purposes. They operate by heating water (or other liquid) to a set temperature until it turns to steam (boils). It transfers that heat in pipes, which displace it through radiators, baseboard heaters, or floors. Most of today's radiators operate off of hot water instead of steam. The hot water is either gravity fed or circulated by a motorized pump.

Boiler Water Hardness

The main ingredient in a boiler system is water. Therefore, it is prudent to determine the quality of the water. A water analysis can identify the composition of your water. Probably the most important determination will be the hardness of the water. This a measure of the water's mineral contaminants by way of chemical analysis or electrical current. Hardness can be reported three different ways: mg/l (milligrams per liter), ppm (parts per million), or gpg (grains per gallon). Hard water is water that has high mineral content.

Water hardness is the primary cause of scale formation in boilers. It is a form of fouling that involves the crystallization of solid salts, oxides and hydroxides. Scale can reduce and block the flow of heat, increase pressure, and increase energy the boiler's expenditure. Treating your water can minimize the formation of scale.

Water-Quality Recommendations

There are three methods for improving the quality of your boiler's water. The first, internal treatment, involves conditioning the water inside the boiler with chemicals such as scale inhibitors, softening agents, oxygen scavengers and anti-priming agents. The chemicals combat impurities entering into the boiler such as hardness, dissolved solids, oxygen and silica. The second method, demineralization (also known as reverse osmosis or electrodialysis), replaces inorganic salts by ion exchange. An ion-exchange water softener works this way. The third method, deaeration, involves atomizing water with steam to remove dissolved oxygen and carbon dioxide.

While any of the above three methods will certainly help, their combined use will further insure water deposits do not reduce boiler efficiency. Remember, a well-maintained boiler not only transfers heat better but also consumes less fuel. A proactive approach to boiler maintenance is far cheaper than a reactive one.