Do I Need a Chemical Inhibitor in my Heating System?

Do I Need a Chemical Inhibitor in my Heating System?

Posted on March 27, 2022

We’ve recently looked at water softeners and magnetic filters and how they can work effectively alongside your heating system to keep it working at its optimum level. 

This week we’re going to look at chemical inhibitors and whether they’re a worthwhile addition and how they help to maintain your heating system and boiler.

What is an Inhibitor ?

First thing’s first – What actually is a chemical inhibitor and how is it different to the magnetic filter that we talked about the other week? It is a chemical liquid that helps to prevent the heating system from corroding and forming system sludge and debris inside the radiators, pipes and boiler. This is different to a magnetic filter, which works by attracting debris to the filter and keeping it from clogging up your pipes and radiators. 

System debris can unfortunately cause big problems, including stopping your heat exchangers from working properly. An inhibitor works by preventing the build up of sludge before it even starts. 

How do I use a chemical Inhibitor in my heating system?

A chemical inhibitor can be added to your central heating system in various ways. 

Depending on what kind of system you have, you can add the chemical by:

  • Adding it directly into your radiators
  • Adding it into the tank in the loft
  • Adding it into the magnetic filter

As we always say, we would recommend that you speak to a qualified heating engineer if you are at all unsure about how to do anything that relates to your boiler or heating system. Our expert heating engineers will be more than happy to help you. 


How to add a chemical inhibitor to a loft tank 

  1. Take a look at how many radiators you have and use this to help determine how much inhibitor you will need to use. 
  2. Stop the flow of water into the system. This could be via a valve on your tank. If there isn’t a valve, then you will need to turn your mains water valve off. 
  3. Empty the water tank.
  4. Have a look at the tank and see what sort of state it is in. If you find that it is corroded or covered in system debris and dirt, then you will need to clean the tank before you carry on. 
  5. Once the tank is empty and clean from debris, empty the inhibitor into the empty tank. 
  6. You can then turn the flow of water back on, either via the valve on the tank or the mains. 

How to add a chemical inhibitor to a combi boiler heating system

  1. Turn off your entire heating system and make sure that your radiators have completely cooled down. 
  2. Choose the radiator you will be adding the chemical to. Shut both radiator valves securely. 
  3. Using the valve you would use to bleed your radiator, apply the scale reducer container securely and then apply the liquid. If it’s a towel rail radiator, just remove the plug on the top and pour the scale reducer in.  Some inhibitors come with a special fitting so no water has to be drained form the radiator, but others you will need to drain some water from the radiator before the chemical can be added.
  4. When you have finished, turn your heating on for about 15 minutes and wait for the inhibitor to travel around your heating system. 


What are the advantages of an inhibitor?

The main benefits of using a chemical inhibitor is that it helps to effectively cut through the dirt and grime and prevent it from building up inside your system.

This means that your water could flow around your heating system at a better rate which would help increase the life of your boiler and system, improve its efficiency and keep the components in good working order for longer. 

Not only does this mean that your heating would work better, but it also means that you could save money. You might be spending money on the chemical, but you’ll potentially be saving money on boiler repairs and replacement parts for those that break down due to the build up of debris and sludge. 


Do I need a magnetic filter as well as an inhibitor?

We’ve recently talked about magnetic filters and why they are a great addition to your heating system. Most boiler manufacturers recommend the use of a chemical inhibitor in addition to a magnetic filter to increase the protection given to your heating system. 

If you’ve recently got a new boiler or you’re planning on getting one soon, then you should definitely be considering getting a magnetic filter installed into your central heating system. 

The earlier you start taking care of your boiler and heating system, the longer it will last and the more efficiently it will work.  

How do I know if I need a chemical inhibitor? 

If you don’t already have a magnetic filter and chemical inhibitor then you might be able to spot some of these tell-tale signs that your boiler is in need of some help:

  • Your boiler has a leak
  • Your radiators feel cooler at the bottom than the top
  • Your boiler seems to struggle to reach the desired temperature
  • Your pumps fail
  • You discover sludge and debris in broken boiler parts

These issues could indicate that your boiler and/or multiple components could break and need replacing which could be costly! 

Installing a magnetic filter and flushing the system with a system cleaning chemical and then adding a chemical inhibitor could prevent a boiler breakdown and keep your heating system running efficiently. 

Want to install a magnetic filter and/or have an inhibitor added to your heating system?  

Get in touch with us today here at Aura Heating – Our friendly team will talk you through the process and our expert Heating Engineers will get it sorted for you in no time. 

You can give us a call on 02393 850849 or email us at You can also find more information on our website. 

Let Aura Heating help you prolong the life of your boiler and heating system with a magnetic filter and chemical inhibitor.