Cold at the bottom of radiators
Sludge settles low in the radiator, so the bottom stays cold while the top gets warm.
MagnaCleanse system flush
Sludge out. Heat back.
Cold spots, noisy boiler, slow-to-heat radiators? A MagnaCleanse removes the black magnetite sludge that chokes your heating, then a magnetic filter and inhibitor keep it clean.
Gas Safe registeredCleaned to BS 7593Filter and inhibitor fitted
Symptoms
Signs your system is full of sludge
Black water when bleeding
Dark, inky water from the bleed valve is magnetite. Clear water with only air means it's air, not sludge.
Noisy boiler
Kettling and banging as sludge restricts flow through the heat exchanger.
Slow to heat up
Blocked radiator waterways and pipes mean heat takes longer to get around the house.
Repeated pump failures
Magnetite is abrasive and magnetic, so it wears pump bearings and rotors.
New boiler going in
Cleaning the system first is part of the installation standard, and protects the new boiler.
The science
What sludge is, and why it matters
Heating systems rust from the inside. The by-product is magnetite, and modern boilers are especially sensitive to it.
Fe₃O₄
Magnetite
Black iron oxide formed when oxygen in system water corrodes steel radiators and pipework.
Source: BS 7593:2019BS 7593
The standard
The code of practice for water treatment: clean the system, protect it with inhibitor, filter it and maintain it.
Source: BSI, BS 7593:20192018
Boiler Plus
Since April 2018, replacement boilers in England must be installed with the system cleaned and treated in line with BS 7593.
Source: GOV.UK, Boiler Plus guidanceYearly
Check and top up
Inhibitor levels should be tested and the magnetic filter cleaned at each annual service.
Source: BS 7593 and filter manufacturers' guidanceWhy modern boilers suffer
High-efficiency condensing boilers have compact heat exchangers with narrow waterways, designed to extract as much heat as possible. That makes them efficient, but it also means a small amount of magnetite can restrict flow, causing hot spots, kettling and eventually failure. Radiators lose output too, because sludge takes up space where hot water should be.
How a MagnaCleanse works
A chemical cleaner loosens deposits, then water is circulated through a powerful magnetic unit that captures the magnetite. Each radiator is isolated and cleaned in turn. Finally a permanent magnetic filter is fitted, and inhibitor is added to slow future corrosion, with the treatment recorded for your warranty.
How it works
Our cleansing process
Test the water
We check the system water condition and inhibitor level.
Clean
Cleaner added and circulated through the magnetic unit, radiator by radiator.
Filter
A MagnaClean magnetic filter fitted or cleaned to catch future debris.
Protect
Inhibitor dosed, system rebalanced and the work recorded for your warranty.
FAQs
System cleaning questions
Will a MagnaCleanse fix my cold radiators?
If the cold patch is at the bottom of the radiator, it's usually sludge, and a cleanse is the right fix. If the cold patch is at the top, it's usually trapped air, and bleeding the radiator is the first step.
How long does a MagnaCleanse take?
For a typical home it's usually completed in a day, depending on how many radiators there are and how bad the sludge is.
Do I need a system clean with a new boiler?
Yes. BS 7593 sets out cleaning, filtering and inhibitor treatment, and replacement boilers in England must be installed in line with it. Most manufacturers also require it to keep the boiler warranty valid.
What's the difference between a MagnaCleanse and a power flush?
A MagnaCleanse uses the system's own pump, a chemical cleaner and a powerful magnetic unit to pull out magnetite, radiator by radiator. A power flush uses a separate high-flow pump. For most systems a MagnaCleanse is quicker and gentler; very heavily sludged systems may need a power flush.
How do I keep the system clean afterwards?
A magnetic filter on the return pipe catches new debris, and the inhibitor level should be checked and topped up at each annual boiler service.
Sources and standards referenced
- BS 7593:2019, code of practice for the preparation, commissioning and maintenance of domestic central heating and cooling water systems
- GOV.UK, Boiler Plus: domestic boiler efficiency standards (April 2018)
- Adey guidance on MagnaCleanse and MagnaClean filters
MagnaClean and MagnaCleanse are trademarks of Adey Innovation Ltd.
Areas covered
System cleansing across Trowbridge and West Wiltshire
Based in Trowbridge, covering a 25-mile radius. Not sure if you're covered? Call and ask.
TrowbridgeBathBristolSwindonFromeYeovilBradford on AvonMelkshamWestburyWarminsterDevizesChippenham