How to Add Inhibitor to Your Central Heating System

Maintaining your central heating system is essential for ensuring its efficiency and longevity. One crucial aspect of this maintenance is the use of an Inhibitor And Protector. In this guide, we’ll cover everything you need to know about using an inhibitor, from its benefits to the practical steps of adding it to your system. Whether you’re a seasoned DIY enthusiast or a homeowner looking to optimise your heating, this guide will help you understand the importance of inhibitors and how to effectively use them.

What is a central heating Inhibitor?

An inhibitor and protector for central heating systems, like the Multipurpose Radiator Inhibitor & Protector from Radiators4u.co.uk, is a chemical solution designed to maintain the efficiency and longevity of your heating system. This 500ml product is suitable for various radiator types and ensures optimal performance by preventing internal issues.

Why you should use inhibitor

1. Prevents Corrosion: It protects metal components in the system from rust and corrosion, extending their lifespan.
2. Reduces Scale Buildup: Inhibitors prevent the formation of limescale, which can clog pipes and reduce heating efficiency.
3. Improves Efficiency: By keeping the system clean and free of debris, it ensures efficient heat distribution, leading to lower energy bills.
4. Maintains System Health: Regular use helps avoid costly repairs by preventing sludge buildup and internal damage.
5. Protects your warranty: Some boiler and radiator manufacturers stipulate the usage of inhibitor as part of their warranty terms.

Do you need to drain the entire central heating system to add inhibitor?

No, you do not need to drain the entire central heating system to add an inhibitor. You can add the inhibitor directly into the system via a radiator, filling loop, or expansion tank, depending on the type of system you have. This makes the process straightforward and convenient, ensuring your heating system remains protected without the need for extensive work.

It may be a good idea to fully drain the system if it has not had a flush in the last 2-3 years to remove any sludge build up and keep your heating in top condition.

How to add inhibitor and protector to your central heating system via a radiator:

Depending on your central heating system you may have an expansion tank or filling loop. If you do, add the inhibitor to the tank or via the filling loop rather than adding directly to the radiator.

1. Turn Off the Heating System: 

Ensure the heating system is turned off and wait for the water to cool down.

2. Choose the correct radiator: 

Select a radiator that is convenient for you to work with. Ideally the highest radiator in the home, as this will reduce the amount of water required to refill the system and reduce air bubbles/locks.

A bathroom towel radiator with top mounted air-vents will make filling the radiator easier.

3. Release Pressure: 

Use a bleed key or flat screwdriver to release any trapped air and lower the water pressure.

CAUTION: Ensure this is done when the radiator is cold to avoid burns.

4. Drain the radiator: 

Close the air vent, then place a bowl below the radiator valve, gently loosen the nut from the radiator to the valve until water starts to trickle. Once it trickles, re-open the air vent and the water should flow. You are aiming to remove up to 600ml of water.

We recommend using a towel below the valve to catch any drips.

5. Close the valve nut: 

Tighten the nut to stem the flow of water, you may find it useful to close the air vent again to reduce the flow.

6. Remove Radiator Plug: 

Remove the plug or vent at the top of the radiator using a spanner. Gently clean the threads of the plug if required with some wire wool or a scouring pad.

7. Add Inhibitor: 

Using an angled funnel or applicator, pour the inhibitor into the radiator. You want to use 500ml for up to 9 radiators. 

If you have 10+ radiators in your system we recommend  2x 500ml Bottles Of Inhibitor.

8. Replace Plug and refill the system: 

Replace the plug and fill the system, if you have a combi boiler then you will have a filler loop to add water to the system. It would be useful to ask someone to open the bleed valve until water flows from the vent then quickly close the air vent. Continue filling the combi boiler until the correct operating pressure is achieved.

9. Restart the System: 

Turn the heating system back on and check for leaks.

10.Bleed the radiator: 

Allow the system to cool slightly then Bleed The Radiator to remove any additional air.

How Much Inhibitor Do You Need?

The amount of inhibitor required depends on the size and capacity of your central heating system. Typically, 500ml of inhibitor is sufficient for a standard domestic system with up to 9 radiators or 100L of water. For larger systems, you may need to use a Double Pack Of Inhibitor & Protector to ensure adequate protection.

How often do you need to add inhibitor to your central heating system?

You should change the water and add an inhibitor in your central heating system every 1 to 2 years. Regular maintenance ensures the system remains efficient, prevents corrosion, and minimises sludge buildup, which can lead to costly repairs and reduced heating performance.

You should also add inhibitor and protector every time you drain the system. 

Is Radiator Inhibitor Worth It?

Yes, using a radiator inhibitor is worth it for several reasons:

1. Prevents Corrosion: Protects metal components from rust and extends the lifespan of your heating system.
2. Reduces Scale Build-Up: Prevents limescale formation, which can obstruct pipes and reduce efficiency.
3. Improves Efficiency: Ensures efficient heat distribution, leading to lower energy bills.
4. Avoids Costly Repairs: Helps prevent sludge build-up and internal damage, reducing the need for expensive maintenance.

Regular use of inhibitors ensures your heating system operates effectively and lasts longer.