Inhibitor & system protection in Macclesfield
In short
Corrosion inhibitor is what stops a heating system generating sludge in the first place. It depletes over time, is lost every time the system is drained or topped up, and its concentration should be checked at each annual service — a test that takes two minutes and is skipped almost everywhere.
Also called: central heating inhibitor · corrosion inhibitor top up · system chemical protection · antifreeze for heating
The chemistry is straightforward. Steel radiators in contact with oxygenated water corrode, producing magnetite and hydrogen. Inhibitor passivates the metal surfaces and suppresses that reaction, and it also protects the dissimilar metals — copper, brass, aluminium — that a system contains from galvanic corrosion. British Standard 7593 expects a system to be cleaned, dosed and then checked annually.
Depletion is the point most people miss. Inhibitor is consumed as it does its job, and it is physically removed every time the system is drained for a radiator change or topped up after a leak. A system that was dosed correctly when the boiler was fitted eight years ago and has been topped up twice since is very likely running unprotected now, and nothing about its behaviour will tell you.
Testing is quick. A sample from a radiator, a test strip or a small kit, and you know whether the concentration is adequate. Doing that at every service costs almost nothing and prevents the far more expensive outcome.
Frost protection is a related product worth knowing about. Where pipework runs through genuinely cold spaces — an unheated loft in an upland property, an outbuilding, a holiday cottage left empty in winter — an inhibitor with antifreeze properties protects the system water itself. It is not a substitute for lagging and sensible frost precautions, but for a property at 300 metres above the town that stands empty for weeks, it is cheap insurance.
Dosing is done through a radiator, a filling loop or a filter housing, and the amount depends on system volume. Underdosing is common; the container's stated coverage assumes a typical system and a large house needs more than one.
What the job covers
- Inhibitor concentration testing at service visits
- Correct dosing calculated from system volume
- Re-dosing after any drain-down, radiator change or repair
- Antifreeze-grade protection for exposed and seasonal properties
- Advice on scale and corrosion products appropriate to soft water
- Record of dose and concentration for future reference
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your plumber has to honour it. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
How often does inhibitor need topping up?
Test annually at the boiler service, and re-dose whenever the system has been drained or repeatedly topped up. There is no fixed interval — the test is what tells you.
Does soft water mean I need less protection?
It means scale is not your problem — but soft water is slightly more corrosive, so inhibitor matters just as much here. The debris in a Macclesfield system is corrosion product, not limescale.
Need this doing in Macclesfield?
Tell us the job and it goes straight to our local plumber — one call back, usually the same day. Free quote, no obligation.