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Not Your Cup Of Tea: What You Need To Know About Kettling In Boilers

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You might have noticed a strange sound coming from your boiler. In fact, it's the same sound your kettle makes when you've put it on the stove; unfortunately, no one's making a nice cup of tea.

This strange sound, also known as "kettling" due to its similarities to a kettle on full boil, can indicate some serious issues going on with your boiler. Left to its own devices, the problem can eventually turn catastrophic and result in the loss of your boiler, not to mention serious injuries for anyone nearby.

The following information will help you understand more about the issues that cause kettling, how it can damage your boiler, and the steps you can take to deal with the problem.

Common Kettling Causes

A buildup of lime scale and other mineral deposits is one of most common causes of kettling on most boilers. Boilers that rely on a "hard" water supply with higher-than-normal amounts of calcium salts tend to be more susceptible to mineral buildup than boilers using "soft" water.

As water heats up inside the boiler, the various salts and mineral deposits fall out of solution and settle along the bottom of the boiler tank. These deposits can also settle within various passageways inside of the boiler, blocking water flow in the process. The resulting restriction causes trapped water to reach its boiling point and eventually flash into steam, hence the kettling sounds.

A faulty thermostat can also cause water within the boiler tank to overheat, creating the conditions for kettling.

How Kettling Damages Your Boiler

When water turns into steam vapor, it expands up to 1,700 times its original volume -- a tremendous amount that puts serious pressure on any vessel not designed for handling steam. Your boiler would normally counteract such pressures by either activating its pressure relief valve or using its expansion tank.

If these measures fail for any reason, your boiler will become more susceptible to water leaks and metal fatigue through constant overheating. Kettling can even cause your pipes and heat exchange to burst, resulting in serious damage to your boiler.

Steps to Take to Solve Kettling Issues

If you suspect kettling in your boiler, then it's time to have it serviced by a dependable technician. Your technician will treat your boiler by removing as much lime scale and mineral buildup as possible. A complete boiler flush can help remove mineral deposits and other contaminants that could harm your boiler over time.

In some cases, kettling can cause enough damage to warrant a complete boiler replacement. It's up to your technician to decide whether to rehabilitate your current boiler or replace it with a newer and more efficient model. For more information, you can visit sites like