A Boiler With a Constant Noise

General Boiler Noises

• The difficulty in determining the source of a boiler noise is that water itself -- specifically, heated water -- creates a variety of physical and biological reactions in a hydronic system and its many components. Water velocity changes as it moves through an amalgam of plumbing lines, fittings and water-handling fixtures, leading to the potential for the gurgling and hammering characteristics of water flow in plumbing. Variations in water temperature, especially in the water boiler, also produce the potential for noises. The biological changes that occur within the water molecules themselves, when heated, create yet another potential source of noise in a water boiler.

Constant Boiler Noise

• The main cause of a constant boiler noise is likely to be the fouling of components within the boiler itself, and the heat exchanger in particular. This fouling is caused by elements already present in the water supply that feeds into the water boiler -- including lime, magnetite, silt and other solids that have dissolved in the water. Any combination of these elements lead to the formation of scaling and sediment that collects not only on the heat exchanger but, as a consequence, on most if not all of the pipes and fixtures found farther down the hydronic line. The implosion of heated water molecules, otherwise known as boiling, then occurs within the boiler itself, resulting in a constant “kettling” sound, even while the boiler is inactive.

Fouled Boiler Solution

• One method used to correct, or prevent, fouling of water-boiler components caused by scaling and sediment buildup is the use of corrosion inhibitors. These solutions introduce chemicals that have been tested and approved for use in hydronic systems. Code standards developed by such organizations as the American National Standards Institute and the National Sanitation Foundation in the United States, and their counterparts and partners across the globe including WRc-NSF in the United Kingdom, help regulate the proper manufacturing of corrosion inhibitors for water boilers.

Softened Water Issues

• Many homeowners install water-softening systems to reduce mineralization and calcification in their water supply. However, this type of water was not recognized as a proper source of fill water for use in hydronic systems due to the assumed potential for corrosion of metals within a hydronic system. As of 2010, corrections to existing code standards applicable to water-supply characteristics and safety had been implemented to include the acceptability of softened water as a fill supply for residential heating systems.