Everything You Need To Know About Power Flushing

What is power flushing?"

Regular power flushing is a key step in maintaining your central heating system in its top condition. Power flushing removes sludge from your central heating system. Sludge such as rusted metal that’s corroded from the pipes. If this debris is kept in your heating system you are not only keeping your system running inefficiently but it could even cause the boiler to break down. So if your central heating isn’t working as efficiently as it used too, power flushing is the best way to solve it.

Power flushing has become a well-known service in our industry – and for good reason. In simple terms, a power flush is a machine which is hooked up to your central heating system and forces chemically treated water through the entire system, dislodging debris and rust (most commonly referred to as ‘sludge’ due to its thick black tar-like appearance) and clearing radiators of cold spots. The sludge is collected within the body of the machine and then disposed of.

This process helps keep your boiler from overworking itself in order to heat your home to the set temperature, reducing costs and the likelihood of an expensive breakdown.

Signs you need a power flush

Signs that your central heating system is in need of a power flush can include;

  • Heating system is extremely slow to warm up
  • Kettling Boiler
  • Cold spots in radiators or some radiators staying cold (which is a sign of a complete blockage)
  • Discoloured water when you bleed the radiators
  • Boiler cycling (turning on and off frequently)
  • Boiler constantly breaking down
  • In consistent water temperatures (combi boiler only)

  • Things to know before power flushing

    When using power flushing equipment, it is important to understand the capability of the equipment, as some pumps within the units are only man enough for a 10 radiator system, where larger units are capable of 20 – 30 radiators. In most instances the requirement on heavily contaminated systems is to clean 1 radiator at a time working through the system in a methodical manner.


    • Faster heating up
    • Radiators produce more heat
    • Boiler will run quieter
    • No cold spots
    • Cheaper gas bill
    • Less risk of breakdown

    • What happens if you don’t power flush?

    • The efficiency will drop which will cost you more money as it takes more fuel to heat the house.
    • It could cause your boiler to break down.
    • Black sludge could ruin carpets etc. if pipes start to leak.

    • Requiring a power flush, especially in relatively new systems, can also be an indicator of an underlying problem with your system which is allowing air into your pipes. Unfortunately in this case, a power flush will not rectify this. You will need a plumber to take a look at the entire system, which may be costly – however likely cheaper than leaving it until the issues get worse.

      Always leave power flushing to a qualified professional. Attempting to do this yourself can lead to severely damaging your boiler or entire system, including bursting pipes and other vital components.