If the system’s dirty, start with a central heating treatment that matches the job. Use a cleaner or flush for debris and sludge, then add an inhibitor once it’s clean. The usual mistake is buying the wrong bottle for the stage you’re at - a cleaner won’t protect a neglected system, and inhibitor alone won’t shift heavy muck.
Corgi Leak Sealer - 500ml Concentrate
Concentrated leak sealer for central heating: 500ml treats 100 litres
Corgi Universal Cleanser - 500ml Concentrate
500ml concentrate cleanser for heating systems
Fernox DS-3 Limescale Remover - 2kg
Powerful sulphamic acid limescale remover with colour-change indicator for water…
Adey MC3 Central Heating Cleaner - 500ml
ADEY MC3 central heating cleaner 500ml, removes sludge quickly
Center Chemical Cleaner Heating System Cleaner - 500ml
Highly concentrated central heating system cleaner, 500ml
Adey MC4 Leak Sealer - 500ml
Central heating leak sealer for sealed systems, 500ml, dosed via MagnaClean® fil…
Fernox Heat Transfer Fluid HP-15 - 20L
Fernox HP-15 heat transfer fluid 20L frost protection to -15°C
Fernox Solar S1 Inhibitor Fluid - 10L
Inhibited heat transfer fluid for solar thermal systems, frost protection to -28…
Sentinel New Build Pack B for Soft Water
New build heating pack for soft water: cleaner, inhibitor, filter.
Sentinel R600 Thermal Fluid - 20L
Thermal fluid for air source heat pumps, frost and corrosion protection, 20 litr…
Start with what the system needs, not the label on the bottle. A central heating treatment only makes sense once you’ve worked out whether you’re dealing with a clean fill, a dirty system, or a job that needs both stages. On a modern condensing setup, system and flue compatibility comes first. Then look at filtration, fuel type, and who’s actually signing it off, especially where Gas Safe fitting applies. One treatment can suit one install and be wrong on another. That is where call-backs start.
If the system is dirty, you are usually choosing between a central heating cleaner, a central heating flush, or a central heating descaler. Cleaner and flush products suit sludge and general contamination. A flush is the harder option when you need to shift heavier deposits before refill.
Descaler is the one to use where scale is the main issue. It will not cover every poor-running system. Once the water is clean, a central heating inhibitor is the normal follow-up because it protects the system rather than cleaning it again. On Central Heating, that is the main split: clean first if you need to, then protect it if you want to avoid the same call-back.
What you buy usually comes down to the state of the system and how much time you have on the job. A central heating treatment for a routine top-up is a different call from a central heating cleaner or central heating flush on a system full of muck. A central heating inhibitor only makes sense when you are protecting clean water rather than shifting deposits.
The common mistake is grabbing the cheapest bottle and expecting it to do two jobs. If you are also picking up fittings or sundries, Central Heating Accessories is the usual next stop. If the job runs into boiler-side parts, Flues & Boiler Accessories is where that decision sits.
Once you’ve picked the treatment, the next question is what the system needs around it. If the install is full of sludge, start with a central heating cleaner or flush before you leave inhibitor in place.
On older systems, sort the filter at the same time. It helps stop the same muck moving back through the circuit. If you’re changing pipework or the boiler side as well, check the related accessories and flue parts before you sign it off. Jobs stall there when the main unit is right but the rest of the kit isn’t.










