Understanding sludge and power flushing
What causes sludge
Over time, water in a heating system reacts with metal pipes and radiators, producing rust and black iron oxide sludge. It collects in radiators, pipes and the boiler.
Power flush vs other cleans
There are gentler ways to clean a system, such as chemical cleaning. A power flush uses higher flow to remove heavier build-up, which suits older or badly affected systems.
Before a new boiler
Manufacturers expect the system to be clean when a new boiler is fitted. Flushing first protects the boiler and supports your warranty.
After the flush
We add inhibitor to the clean system to help slow future corrosion. Combined with regular servicing, it keeps the system healthier for longer.
Signs your system needs a power flush
The most common sign is radiators that are warm at the top but cold at the bottom, even after bleeding. Others include the heating taking longer to warm up than it used to, dark or dirty water coming out when you bleed a radiator, a boiler that's noisy or keeps cutting out, and radiators that need bleeding again and again. On their own, some of these can have other causes, so we check before recommending a flush.
What happens on the day
We connect the flushing machine to the system, usually at the pump or a radiator. Cleaning chemicals are circulated at high flow to loosen sludge, and we work through each radiator in turn so debris is lifted and removed rather than moved elsewhere. Once the water runs clear, the system is refilled, dosed with inhibitor, bled and balanced. We then check every radiator is heating properly before we leave.
Keeping the system clean afterwards
After a flush, inhibitor helps slow new corrosion. An annual boiler service is a good time to check the system is staying clean. If your system is prone to sludge, we can advise on further protection.
Power flushing before a boiler installation
When we quote for a new boiler, we look at the condition of the existing system. If there's significant sludge, we'll recommend a power flush before the new boiler is connected. Debris from an old system can block the new boiler's heat exchanger, reduce efficiency and cause faults, and manufacturers expect the system to be clean. Doing it at the same time as the installation is the most practical approach.
We carry out power flushing across Fareham, Gosport, Stubbington, Portchester, Titchfield, Locks Heath, Park Gate, Warsash, Whiteley, Lee-on-the-Solent, Portsmouth and Southampton.
Power flushing for landlords
Sludge-related problems such as cold radiators and noisy boilers are a common source of tenant complaints. A power flush between tenancies, followed by an annual boiler service, keeps the system healthier and reduces call-outs.
Power flush or new radiators?
Cold radiators don't always need replacing. If the radiator itself is sound and the problem is sludge, a power flush restores heat across the whole system for less than the cost of replacing several radiators. If a radiator is corroded or leaking, replacement is the better option. We'll tell you which applies.
Where we work
We carry out power flushing for homeowners and landlords across Fareham, Gosport, Stubbington, Portsmouth, Southampton, Titchfield, Portchester, Lee-on-the-Solent, Locks Heath, Park Gate, Warsash and Whiteley.
