Why Should I Use A Central Heating Inhibitor?

Central Heating Inhibitor: What Is It?

A central heating inhibitor is a chemical solution designed to protect your central heating system for more efficient, longer-term use.

Typically, it is clear or pale yellow in colour and contains active ingredients including potassium tetraborate tetrahydrate, disodium molybdate, sodium nitrate and 2,2′,2”-nitrilotriethanol.

Like most chemicals, special care should be taken, including storage in its original vessel, which is kept out of direct sunlight in a place that is cool and well-ventilated.

What Does a Central Heating Inhibitor Do?

Central heating systems inevitably suffer from issues such as rust, dirt and limescale.

Over time, this results in a thick, gloopy substance, collecting at the bottom of your pipes, as well as in the radiator. Acting much like a dam, this sludge can develop to the point that water is unable to pass through the system – making it difficult for radiators to heat up efficiently.

Your central heating inhibitor is the top weapon in your arsenal against this sludge. The active ingredients of the central heating inhibitor work together to deliver a chemical reaction strong enough to break down present sludge, while protecting against future build-up.

What Happens If I Don’t Use A Central Heating Inhibitor?

Overlooking sludge in the system has a direct impact on your bottom line. Without it, you could be face more expensive heating bills as well as repair costs for issues which could easily be prevented by using a central heating inhibitor. Of course, there’s also a risk of invalidation of the warranty on your boiler – which is a significantly higher cost.

How Much Central Heating Inhibitor Do I Need?

Typically, you should use the full bottle of central heating inhibitor when adding as it ensures a sufficient level to pump through the system. Often, this is supplied in 1.0 litre quantities.

Sometimes concentrations and levels vary depending on how many radiators are included in the system. Always check the manufacturer’s instructions beforehand for absolute certainty. These are usually found on the bottle’s reverse label.

Importantly, your central heating system can never have *too much* inhibitor in it. The more that is there, the greater protection you can expect.

Adding Central Heating Inhibitor: A Step-By-Step Guide

If you’ve never done this before, then fear not. It’s a fairly straightforward task and we’ve prepared a few different ways to do it, depending on your heating system.

Combi-Boiler Heating Systems

Many homes in the UK use this type of heating system. Typically, you will need approximately an hour – including time for bleeding the radiators at the end.

To complete this task, you’ll need a spanner as well as the appropriate amount of central heating inhibitor. Please note, if your inhibitor isn’t supplied with a dosing adapter, you will need a funnel and/or tubing.

1. Switch off the heating system and allow the radiators to cool completely before proceeding
2. Drain your heating system
3. Shut down the system’s drain valve using a clockwise movement. (Usually, this is on an outside wall or at the lowest part of your plumbing pipes.)
4. Unscrew the radiator’s bleed plug using a spanner.
5. Attach the dosing adaptor or combination of funnel and flexible tubing to one radiator. (Only one radiator needs to be treated to look after the system.)
6. Slowly pour the inhibitor into the system.
7. Once complete, remove your dosing adaptor or funnel.
8. Replace and tighten the bleed plug. Use a spanner for a secure fit but do be careful to avoid overtightening.
9. Turn the radiator valves back on using an anti-clockwise movement.
10. Check the pressure of your boiler and top up as necessary. The standard pressure for boilers is approximately 1.5 bar. However, this can vary between manufacturers. Always check provided guidance.
11. Bleed your radiators, as part of good practice.

Closed Heating Systems

The process for this type of central heating system is slightly different.

When working with this type of system, remember that water cannot be displaced in a sealed system. Before adding the inhibitor, you may need to drain some water first so there will be enough room for it to get in there and do its work.

If your sealed heating system has an expansion vessel, then you will need to add an inhibitor via a filling loop, rather than directly into the system.

Open-Vented Systems

With open-vented central heating systems featuring a large water tank, as well as a small expansion one, the inhibitor should only be added to the smaller of the two.

The nature of this system means that extra care needs to be taken. Always make sure your water is switched off at the mains or via the tank’s valve.

Do check that your tank is looking clean and free from corrosion before you add a central heating inhibitor. If your tank looks in need of a good clean, take care of that before the inhibitor is introduced.

How Often Should It Be Changed?

Dilution over time means that central heating inhibitors must be replaced regularly if your system is to be protected against efficiency-reducing debris.

Typically, the central heating inhibitor is effective for a year and should be tested and added by heating engineers during the annual service.

To help you keep an eye on between tests – particularly if your system is slow to heat up – central inhibitor testing kits are available. Easy to use, they provide you with the concentration of inhibitor currently in the system… and all it requires is a sample of radiator water.

Closing Thoughts

Your central heating inhibitor plays a crucial role in the health and longevity of your system. This hero not only breaks sludge down, but it also protects against breakdowns while extending the life and value of your boiler investment. Take a look at our central heating radiators today.

If you have any questions, please contact us today. Our knowledgeable team of experts are always on hand to assist you.