Published on

pH Levels in Commercial Boilers: Tips to Extend the Life of Your Boiler System

Your commercial boiler is essential to running your property and keeping your tenants happy. Did you know that pH levels in commercial boilers can cause your boiler to fail long before its natural lifespan or can extend the life of your boiler system? Here’s an overview of why pH is so important to your boiler and how it’s regulated for optimum boiler performance.

What Is pH Anyway?

Measuring acidity and alkalinity

Before we get into further discussion about how to adjust your commercial boiler’s pH, it’s helpful to review exactly what pH is. Short for “potential of hydrogen,” pH is simply the logarithmic measure of the strength of a weak acid. In other words, it’s a way to quantify how acidic something, like a liquid, is.

There is a scale used to express pH, which goes from zero to 14. A pH of 7, in the middle, is considered neutral. Anything between zero and 7 is acidic, while substances with a pH between 7 and 14 are considered alkaline (also known as basic). Because pH is denoted on a logarithmic scale, a pH of 3 is 10 times more acidic than a pH of 2, for example.

Why Is Your Boiler’s pH So Important?

Boiler efficiency and lifespan

Pure water has a pH of 7. However, water is almost never pure because it has chemicals in it that make it either basic or acidic. Boiler systems run into trouble when the water they hold and distribute becomes too far to one end or the other of the pH spectrum. Typically, too much acidity is a common problem that can shorten the lifespan of a commercial boiler, but very high alkalinity can also cause boiler disasters.

Boiler water acidity should be avoided because it’s corrosive. Over time, this corrosion can wear holes into your boiler tank and plumbing, causing leaks and significant wasted water, which in turn costs property owners money. Below a pH of about 8.5, an acid attack can occur, leaving your boiler pitted, which is often the first sign that worse damage is to come.

New York City’s municipal water leans toward the slightly soft side. But it’s worth noting that even slightly hard water can be worse for your boiler if it’s also acidic. Water with a low pH tends to form mineral scale encrustation that precipitates harmlessly out with more alkaline water.

Extremely high alkalinity can lead to a caustic attack. This can also corrode the boiler via gouging or cracking (also known as embrittlement). This is just as bad as an acid attack and can result in you having to replace your boiler years before you anticipated. High alkalinity can also cause foaming, which can lead to inefficient steam production or even having to shut down your boiler – also undesirable.

What Is the Ideal pH Level for a Commercial Boiler?

Avoiding excess acidity

Commercial boiler pH levels should lean toward alkalinity and avoid acidity. There are different pH ranges suggested, usually between 8 and 10.

How Do You Control Your Boiler’s pH Level?

Water treatment options

Treating your boiler’s water is the key to achieving the correct pH level. Water treatment can entail removing impurities that alter the pH or adding chemicals to neutralize acidity. Some of the compounds used most frequently include:

• Sulfites (oxygen scavenger) to remove dissolved oxygen that comes from aerated water supply but causes corrosion
• Phosphates to counteract calcium compounds that cause excess hardness
• Sodium hydroxide and potassium hydroxide to reduce the production of carbon dioxide and increase alkalinity
• Amines to protect steam return lines

But how do you know what the pH is before you start? Water testing should be performed before creating a water treatment regimen. For the greatest accuracy, cold water from the boiler feeder should be the testing source for boiler tank water.

In the old days, building managers used litmus paper to test pH levels. Then came portable handheld pH testers that are still in use today and are handy if you also wish to test the pH of the water in your cooling towers. The most sophisticated boiler systems have pH monitoring integrated into their automated boiler controls. They not only test pH regularly but also adjust treatment accordingly based on the results, freeing up manpower and giving property owners more peace of mind.

These kinds of monitors are also available now to monitor the pH of your condensate that’s returned via your steam traps. Your steam return lines extend the life of your boiler, so you want to make sure they’re not subject to corrosion either.

The steam in your system may not be the same pH as your boiler tank water. Why? Carbonates and bicarbonates in the water break down in the boiling process, becoming first carbon dioxide and then carbonic acid in the steam system. Carbonic acid removes the thin protective layer of rust in most steam pipes, subjecting them to corrosion.

If you suspect your boiler needs a pH adjustment, or if you would like to automate the pH regulation process for greater efficiency, Calray Boilers can help. Call us at 212-722-5506 or reach out online to schedule a service call. Don’t wait until the wrong boiler pH puts your system in jeopardy. Get in touch today.