My Boiler Has a Kettling Noise & Water Pressure

Kettling Noise

• While not silent, boilers aren’t supposed to make the bubbling noise of a hot water kettle just about to reach the boiling point. If you can hear that noise in your boiler near the heat exchanger, it's a warning that the water in that area isn’t moving through at high enough speeds or with sufficient pressure behind it. The sound is caused by water reaching the boiling point inside the boiler.

Causes

• Kettling can be caused by the buildup of scale inside the boiler. Scale is caused by mineral deposits from high levels of calcium or magnesium in the water used in the boiler. The scale traps air in the system, reducing the volume of water moving through the heat exchanger. The reduced volume allows the water to reach a higher temperature. If the water pump isn’t moving enough water through the system, the lower water pressure can open the door to higher than normal water temperatures.

Solutions

• Removing scale from the boiler can prevent the kettling problem. You can flush the system with a descaling solution, which removes mineral buildup. Installing a filter on the water supply will remove problem minerals before the water enters the system. If the issue is insufficient water pressure, have the water pump on the boiler system serviced by a professional technician. She can either repair the malfunction or replace it with new parts.

Considerations

• Don’t ignore a kettling sound in your boiler; it's an indication of a problem within the system. Despite its name, the boiler shouldn’t contain boiling water. An inability to maintain steady water pressure or a standard temperature could eventually shorten the life of your boiler system. Having your system serviced regularly can reduce the risk of problems such as kettling and low water pressure in the future.