Have you ever noticed white, chalky buildup inside a kettle? That’s called scale, and it’s a big problem for boilers too! But why does scale form in boilers, and how can we prevent it? Let’s break it down in simple terms.

3 Main Causes of Scale Buildup

1. Using Hard Water Instead of Soft/Pure Water

•   Natural water (“raw water”) contains minerals like calcium and magnesium. 
•   When this water is heated in a boiler, the minerals don’t evaporate—they get left behind and build up as scale. 

2. Incorrect pH Levels in Boiler Water

• If the water is too acidic or too alkaline, it speeds up scale formation. 

3. High Concentration of Impurities

• The more impurities in the water, the faster scale forms. 

How Does Scale Actually Form?

Think of a boiling kettle: 

• Water turns to steam and escapes, but minerals like calcium, magnesium, and silica stay behind. 
• Over time, these minerals get so concentrated that they stick to the boiler’s walls and pipes as hard, crusty scale.

How to Prevent Scale: Inside/Outside the Boiler

1. External Water Treatment (Before Water Enters the Boiler)

• Water Softeners: Remove calcium and magnesium. 
• Pure Water Systems: Remove almost all impurities. 
• Deaerators: Remove oxygen to prevent rust. 
• Filters: Trap dirt and particles. 

2. Internal Water Treatment (Inside the Boiler)

• Adding Chemicals: “Boiler cleaners” help keep surfaces scale-free. 
• Blowdown: Regularly draining some boiler water removes concentrated impurities.

“But We Have a Softener—Why Is There Still Scale?”

Even with the right equipment, scale can still form if:

• The softener isn’t maintained properly.
• Too much water is pushed through the system.
• The water contains silica (which softeners can’t remove).
• Internal treatment (like blowdown) is neglected.

Why Is Scale So Dangerous?

• Acts like insulation, making the boiler less efficient (wastes energy!).
• Can cause overheating, leading to bulging pipes or even bursts.

3 Simple Ways to Prevent Scale

1. Use Softened Water – Removes hardness minerals.
2. Use Boiler Cleaners – Keeps the inside of the boiler clean.
3. Perform Blowdown – Flushes out concentrated impurities.

Final Thought:
“Scale doesn’t form overnight—but ignoring it can lead to big problems. A little prevention saves a lot of trouble!”

Next time, we’ll take a closer look at why boilers need soft water.