Assessment result explained

What inhibitor testing can tell you

Heating inhibitor is a protective chemical treatment. An inhibitor result can support a wider view of system protection, but it should be considered with turbidity, pH, system history and applicable manufacturer guidance.

Why protection can change

Water loss or dilution

Draining, leaks, topping up or other work can reduce or change the concentration of existing treatment.

System condition

Contamination, sludge and water balance can affect the wider picture even when inhibitor has been added.

Time and maintenance

Monitoring may be useful after work or as part of planned care, but the appropriate interval depends on the system and relevant instructions.

Protection is not the same as diagnosis

A single kit result does not prove that corrosion is present or absent, confirm that protection is universally adequate or determine that more chemical must be added.

Adding inhibitor alone may not address existing contamination, sludge, circulation problems or faults. Consider all Assessment results and the wider circumstances before taking action.

Manufacturer- and system-specific instructions take precedence over any general monitoring interval.

Put the result in context

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FAQs

What is central heating inhibitor?

Central heating inhibitor is a protective chemical added to heating system water to help reduce corrosion inside radiators, pipework, pumps, valves and boiler components.
It helps support long-term system protection by reducing the conditions that allow rust, corrosion by-products and sludge to develop.

Can I add inhibitor directly to a dirty or sludgy heating system?

If a heating system already contains heavy contamination or sludge, adding inhibitor alone may not solve the underlying problem.
Inhibitor is designed to help protect clean or correctly treated system water. Where contamination is already present, cleaning, flushing or further investigation may be needed before protection levels are restored.

How do I know if my inhibitor level is too low?

Inhibitor cannot usually be judged by looking at the heating system from the outside.
The most reliable way to understand inhibitor protection is to test the system water. A Heating System Health Assessment can help show whether inhibitor levels appear to be within the expected range or whether system protection may require attention.

How long does inhibitor last inside a heating system?

Inhibitor does not last forever. Its effectiveness can reduce over time due to heat, dilution from top-ups, leaks, system work or natural degradation.
Regular testing helps monitor whether protection levels remain suitable and whether further maintenance may be worth considering.

What happens if I run my heating system with no inhibitor?

Without enough inhibitor protection, system water may become more likely to contribute to corrosion inside radiators, pipework and boiler components.
Over time, this can lead to the formation of contamination such as magnetite sludge, reduced water quality, poorer circulation and increased wear on system components.