Have you ever noticed your boiler system giving off a deep, rumbling sound? If so, don’t worry. Your boiler probably isn’t going to explode. It is, however, in a bit of trouble. That rumbling sound is called “kettling,” and it’s a serious threat to the health of your boiler. If you don’t deal with it, you may end up having to replace your boiler. Let’s take a look at what causes kettling, and what you can do to stop it.
The Cause of Kettling
Kettling is caused by hard water, which is water with a very high magnesium and calcium content. As hard water flows through your boiler’s heat exchanger, it deposits small amounts of these minerals on the walls of the pipe. These mineral deposits eventually form into lime scale, which grows large enough to restrict the flow of water through the heat exchanger.
As the water gets trapped in the heat exchanger for too long, it evaporates into steam. The rapid expansion of the steam puts pressure on the walls of the heat exchanger, which it wasn’t designed to handle. The rumbling sound you hear is the heat exchanger struggling to contain all the steam building up inside it. If this problem is not addressed, the heat exchanger could eventually rupture and cause a great deal of water damage to the surrounding area.
The best way to deal with kettling is to turn off your boiler and call for repairs as soon as you hear it. The faster we can repair your boiler, the more damage we can prevent. Typically, all it takes to stop kettling is to scrape all of the lime scale out of the heat exchanger.