Cold at the bottom
Radiators warm at the top but cold at the bottom are full of sludge. Cold at the top usually just needs bleeding.
Power flushing · Croydon
Power flushing in Croydon
Years of rust and sludge settle in radiators and pipes, starving the boiler of flow. A power flush pushes it all out, so radiators heat evenly and the boiler stops struggling.
Gas Safe registeredNo. 567789Free quote · 1 of 11 Saved
Prefer to talk? Call 020 3856 8293
- Gas Safe No. 567789Check us on the register
- Fixed written quoteThe price you agree is the price
- Building Regs notifiedCertificate posted to you
- Warranty registeredWith the manufacturer, for you
Signs you need one
Does your system need flushing?
Banging or kettling
Restricted flow makes the boiler overheat locally and boil, which you hear as kettle-like rumbling.
Black water when bleeding
Dark, dirty water from the bleed valve is magnetite: rust sludge circulating in the system.
Slow to warm up
Rooms take ages to heat even with the boiler running flat out.
Repeated pump failures
Sludge wears pumps and blocks heat exchangers. Replacing the part without cleaning the system is a short-term fix.
Fitting a new boiler
A clean system protects the new boiler and keeps the warranty valid.
How it works
How a power flush works
- 1
Check the system
We look at the radiators, valves and pipework first, and tell you if anything looks too weak to flush.
- 2
Connect the pump
A flushing pump connects to the system, usually where the circulating pump sits, and pushes water through at high flow.
- 3
Clean radiator by radiator
Cleaning chemicals loosen the sludge, and each radiator is flushed in turn until the water runs clear.
- 4
Protect it
The system is refilled with inhibitor to slow new corrosion, and a magnetic filter is fitted if you don’t have one.
Is it worth it?
When a power flush makes sense, and when it doesn’t
A flush is worth it when sludge is the problem: cold spots, a noisy boiler, dirty water. It won’t fix a failing part, and on a very old system with weak radiators it can do more harm than good. We’ll tell you honestly which you’ve got.
Planning a new boiler anyway? The system clean is part of a proper installation. See boiler replacement.
FAQ
Power flush questions
How long does a power flush take?
Usually most of a day for an average house. More radiators, or a very sludged system, takes longer.
Do I need a power flush before a new boiler?
The system must be cleaned before a new boiler goes on, and manufacturers expect it. Whether that means a full power flush or a chemical clean depends on how dirty the system is. We’ll check and tell you.
Can a power flush cause leaks?
On an old system, sludge can sometimes be the only thing sealing a weak joint or a corroded radiator. A flush can reveal it. We check the system first and tell you if we think that’s a risk.
Will it fix my noisy boiler?
If the noise is “kettling” from sludge or scale in the heat exchanger, often yes. If it’s a failing pump or fan, a flush won’t help, and we’ll tell you which it is.
More boiler help
- Boiler installationNew boilers fitted across Croydon
- Combi boilersHot water on demand, no tanks
- Boiler replacementSwap an old or broken boiler
- ConversionsSystem, regular or back boiler to combi
- Boiler repairBreakdowns, leaks, fault codes
- Boiler servicingAnnual service and landlord certificates
- Installation costWhat decides the price
- Emergency repairNo heating or hot water today
- Landlord certificatesAnnual gas safety record (CP12)
- Moving a boilerNew room, new wall or the loft
Book a power flush
Tell us what the radiators are doing and how many there are.