Why is plain water not enough for home heating? — 4 scientific reasons

Why is plain water not enough for a heating system or radiator?

Many homeowners think that because it’s cheap and readily available, they can use it directly in their heating system or radiator package. But in practice, plain water — even drinking water or reverse osmosis water — is one of the biggest enemies of heating systems. It contains salts, dissolved oxygen, and sometimes bacteria that, over time, cause scale, corrosion, foam, and reduced efficiency. In this guide, we’ll explore four scientific and practical reasons why plain water should never replace specialized chemicals.

1. Plain water causes scale to form on heating pipes

Town water or rural well water is usually hard — that is, it contains calcium (⁺Ca²) and magnesium (⁺Mg²) ions. When this water is heated in a heat exchanger or heating pipes:

• Calcium carbonate (CaCO₃) precipitates
• Sulfates and silica also precipitate at high temperatures

These scale layers:

• Reduce heat transfer by up to 20%
• Cause higher heat loads on the package or boiler
• In the long run, they lead to pump failure or burst pipes

Practical tip: Even RO (reverse osmosis) water is not completely pure and may contain silica or sulfates that precipitate at high temperatures.

2. Plain water corrodes system metals

Heating systems consist of copper (pipes), steel (radiators), cast iron (package), and sometimes aluminum.

Plain water:

• Contains dissolved oxygen that gradually oxidizes metals
• Its pH is inappropriate (usually between 6.5 and 7.5) — while it should be between 8.5 and 10 to prevent corrosion
• In dead spots (such as dead pipes), localized corrosion accelerates

Result:

• The circulating water turns red or brown (rust)
• Radiators rot from the inside
• Sudden leaks occur in winter

3. Plain water causes foam and gas formation in the system

• Water contains some oxygen and nitrogen
• When heated, these gases are released and create foam

Frost causes:

• Reduced pump efficiency
• Rumbling or boiling sounds in the system
• Errors in temperature and pressure sensors

In systems with open expansion sources (such as some villas), this problem is more severe.

4. Plain water freezes in winter and boils in summer

Even if we ignore chemical problems:

• Pure water freezes at 0C° — it only takes one very cold night for the pipes to crack
• The boiling point of water is 100C° — on warm winter days or in compressed packages, the temperature may exceed this limit

In contrast, specialized solutions

• Lower the freezing point to -48 degrees
• Raise the boiling point to +120 degrees

❓❓❓ Common questions from home users ❓❓❓

❓ Is mineral water or distilled water a good alternative?

No. Mineral water contains more salts. Distilled water also only reduces oxygen, but does not change the hardness or pH. None of this prevents scaling, corrosion, or freezing.

❓ Why is my new package fine with plain water?

Maybe hidden damage hasn’t appeared yet. Corrosion and scaling take years to show up — but once they do, they are irreversible.

❓ Can I just use RO water?

RO water reduces the risk of scaling, but:

• It still has dissolved oxygen
• It has a low pH (typically 5.5–6.5)
• It lacks anti-corrosion agents

So, even with RO water, it is necessary to inject protective chemicals.

Conclusion: Cheap water = expensive costs

Using plain water is a short-term saving that in the long run leads to:

• Increased gas or electricity consumption (due to reduced efficiency)
• Early replacement of radiators or packages
• Emergency repair costs in the cold of winter

In contrast, a specialized multi-purpose solution (anti-scaling, anti-boiling, anti-corrosion, anti-foam) not only protects the system, but also increases its life by two to three times.

If you are still using plain water, empty the system today and inject the appropriate solution after washing. This small decision can add years to the life of your equipment.

If you need expert advice to identify the type of sediment or the optimal selection of chemicals, Abrizan Company specialists, with more than 20 years of experience in advanced laboratories, are ready to provide customized solutions to various industries.

☎️Free call and consultation with Abrizan specialists☎️