As central heating systems age they can reduce in efficiency and heat output if not carefully maintained. One of the most common causes of reduced output and efficiency is a combination of magnetite, rust, scale and other debris, commonly referred to as ‘sludge’. Sludge can have a detrimental effect on your heating system, reducing the lifespan of your boiler, blocking pipework, causing poor heat output from your radiators, and generally making the whole system less reliable.
One of the most common and effective methods of dealing with sludge is to have your system powerflushed. This helps to remove the sludge from the central heating system, and restore it back to its former glory.

A powerflush is now also required when installing a new boiler onto an old system in accordance with Part L of the UK Building Regulations for England and Wales, and a corrosion and scale inhibitor chemical must be added during commissioning.

So what are the common signs of needing a powerflush? Here are some to look out for:

  • Noisy boiler (banging, clattering etc)
  • Cold spots on radiators
  • Radiators constantly need bleeding
  • Noisy radiators
  • Blocked pipework
  • Murky / discoloured / black system water
  • Persistent system breakdowns
  • Poor system temperature
  • Boiler cycling on and off

What are the benefits of a powerflush?

  • Extended boiler life
  • Extended system life
  • Reduced operating noise
  • Validate boiler warranty
  • Reduced fuel bill
  • Improved system flow
  • Improve system reliability
  • More even heat distribution throughout
  • Reduced need to bleed radiators

So how does it work?

A chemical is added to the central heating system either prior to carrying out the powerflush, or at the start of the powerflush to help with the process of breaking down the sludge.
The powerflushing machine is then attached to the system either via the circulating pump, the radiator tails, or any other means that is practical. Water is then pushed around the system at high velocity, and can be switched direction in an instant to help agitate and dislodge sludge build-ups, ensuring a thorough cleansing of the system, and restoring the system to optimum operation.
Once the sludge has been removed from the system, fresh water is introduced into the system forcing the contaminated water out. An inhibitor is also added to the system to help protect and prevent future corrosion from occurring. The system is then restored to normal operating conditions.


These images show the before and after of a radiator suffering from magnetite (sludge) build up taken using an infrared camera.
In the first image, there is a clear cold spot caused by the build up of the sludge as shown by the dark blue area toward the middle of the radiator.
The second radiator is after a powerflush, and shows the successful removal of the sludge build up in the radiator. It is clear to see the heat is now spread evenly throughout the radiator.


To further protect your system
We also recommend a central heating system filter to help keep your system free from any build up of sludge, and further protect your boiler and radiators. We can supply and install these as part of the powerflush, or they can be installed on their own.


To book a powerflush
We are able to provide powerflushing to the Hull, Hessle, Willerby, Beverley, Hornsea and surrounding areas. For more information or to arrange a visit call us on 01482 762692 or click ‘Book Appointment’ and be confident in our free quotations, completely transparent prices and no call-out charges.