Your boiler can have different issues, ranging from issues with your HVAC to complications with your pipelines. Maintaining it is necessary to ensure that you have proper heating in your living spaces. For people who own residential complexes, it’s more than just a living essential; it’s also a crucial contributor to their revenue stream.

A growing concern among boiler owners is the tricky issue of corrosion. Unlike worn out parts that are solvable through replacements, leaving your boiler untreated for rust can make your entire heating systems unusable. This is why it’s necessary to understand how to protect your boiler from rusting.

Summarising the effects of corrosion on boilers

When iron interacts with water, a chemical compound called ferrous hydroxide forms. If there’s dissolved oxygen in the area, it will combine with the chemical compound to create the reaction that generates corrosion. This process continues over time, as long as dissolved oxygen and ferrous hydroxide is present. For this reason, it’s necessary to prevent moisture and humidity around metal surfaces. Otherwise, corrosion will speed up faster and undetected.

For boilers, corrosion can create holes in different components, such as tubes or feedwater piping. This can manifest in various issues that range from simple plumbing leaks to system malfunctions. The degree of damage your boiler will sustain will depend on the type of corrosion it experiences.

Analysing the different kinds of boiler corrosion

Since metal can react with water in different conditions, the kind of corrosion your boiler will experience will vary. Each one varies in degree of severity and root cause. Here are three kinds you should be cautious of:

  1. Galvanic corrosion: Not all metals agree with each other, with the introduction of electrical contact creating galvanic corrosion. This is the degradation of interacting metals near a juncture or joint between two dissimilar metals.
  2. Caustic corrosion: A boiler’s magnetite layer can chemically react against caustic substances. This usually happens due to boiler water with high pH or acidity levels. For this reason, it’s necessary to be mindful of your water’s pH to protect your boiler systems.
  3. Pitting corrosion: Among all the kinds of corrosion possible, pitting corrosion is the most problematic. It’s a localised corrosion that forms from a small source of corrosion due to oxygen in the feedwater. If your boiler shows signs of pitting, you may require chemical treatment to resolve the full extent of the damage.

Analysing how each type occurs can give you a better idea of detecting the source of damage to your boiler.

Understanding the right response to prevent boiler corrosion

Although detecting signs of corrosion is necessary to repair your boiler, you can also protect your boiler in advance by employing the right preventative practices. Having a logbook to track your boiler’s operation is an excellent way to monitor pressure, temperature, and pH changes. Doing so will point you to the right solution, depending on your boiler’s condition. You may have to use additives to ensure proper oxygen absorption or install a deaerator to clear away gasses from your feed water. Remember to consult a boiler expert before you attempt to remedy your boiler’s situation.


Chemical damage can seem like an irreversible issue for boilers. However, it’s still a manageable issue if you make the right decisions. With the right specialist to confirm your remedy, you can maintain your boiler back to good health for more prolonged use.

If you’re looking for temporary boiler rentals in London, we’re the right company to call. At London Climate Hire, our HVAC specialists can repair, maintain and supply you with all your boiler needs. Contact our boiler experts today to get a full list of our services.