JOB / SE13 / 8 RADS
A Lewisham terrace, SE13: eight radiators, five cold at the bottom, water like espresso at the first bleed; flushed in a day, every radiator even by evening, before-and-after samples left on the kitchen counter.
If your radiators are cold at the bottom, your boiler kettles like an old stovetop and the system takes an age to warm up, the problem is probably not a part. It is the water. Years of rust and debris settle into a black magnetite sludge that strangles flow, steals efficiency and quietly shortens your boiler's life. A professional power flush drives it out. Our engineers power flush central heating systems across every London borough at fixed per-radiator prices from £350, finished with inhibitor and, where the system deserves it, a magnetic filter that keeps the water clean for years. And because power flushing is the most over-sold service in heating, we start every job with an honest assessment of whether you actually need one.
Average reply under 10 minutes. No obligation.
Call 020 3000 0000Inside every wet central heating system, steel radiators and water are having a slow argument, and rust is the result. Add the limescale that London's famously hard water bakes onto every hot surface, plus the debris every system collects over years of small works, and you get magnetite: a black, magnetic sediment that settles wherever the flow is slowest. The bottom of radiators. The tightest bends. The boiler's own heat exchanger. Flow drops, rooms cool, the boiler works harder for less, and eventually a £2,000 heat exchanger fails doing a job dirty water made impossible. Every year without inhibitor protection accelerates all of it, which is why the systems we flush are so often the ones nobody has touched in a decade.
System check and honest verdict on whether a flush is the right answer at all.
Purpose-built flushing unit plumbed into the system, ready to circulate.
High flow, low pressure, radiator by radiator, with targeted attention on stubborn cold spots.
System refilled and dosed with corrosion inhibitor to protect what we just cleaned.
Before-and-after water samples shown; every radiator confirmed heating evenly top to bottom.
Power flushing is heating's most over-sold service, and we would rather tell you the truth than sell you a day's work. One cold radiator does not need a whole-system flush; it may need bleeding, a TRV, or a single-radiator flush at a fraction of the cost. A system that is merely unbalanced needs balancing, not chemicals. A newer system with a working filter and healthy inhibitor levels almost never needs flushing, whatever a quote-hungry engineer says. And a system with very old, fragile pipework sometimes should not be power flushed at all; a gentler chemical cleanse is the safer route, and we will say so. If our assessment finds you do not need a flush, you will hear exactly that, along with what you actually need instead.
A flush is only as good as what follows it. Every job ends with a full inhibitor dose, recorded so your annual service can check the level rather than guess. A magnetic filter keeps collecting what chemistry cannot prevent. And here is the connection many Londoners meet the hard way: manufacturers require a clean system for a new boiler's warranty, and a warranty claim on a sludged system can be refused. If you are planning a new boiler, the flush is not an extra; it is the condition. We coordinate both, and our installation quotes already include the appropriate clean. Read more on our boiler installation page.
A Lewisham terrace, SE13: eight radiators, five cold at the bottom, water like espresso at the first bleed; flushed in a day, every radiator even by evening, before-and-after samples left on the kitchen counter.
A Hanwell semi, W7: one stubborn radiator, quoted a single-radiator flush instead of the whole-house job a previous firm had pushed; £120 and done.
A Winchmore Hill house, N21: flush plus magnetic filter ahead of a new boiler installation, warranty condition met, paperwork filed with the boiler's registration.
Fixed per-radiator prices, before-and-after proof, and an assessment that will tell you if you do not need us. Call 020 3000 0000 or request a callback, and mention what your radiator water looked like at the last bleed; it tells us half the story before we arrive.