Following on from last months look at water treatment I thought it would be useful to have a more in-depth look at power flushing of heating systems.

Do you need a power flush?
If you have any of the following symptoms you could potentially benefit from a power flush.

  • Heat circulation problems including reduced heat output and slow heat up times.
  • Cold areas on radiators.
  • Blocked radiators or pin hole leaks on radiators.
  • Boiler noise, failure or lockout.
  • Noisy or broken pump.
  • Discoloured or black water circulating in the heating system.
  • Any of these symptoms may point to the need for a power flush, but an inspection by a professional -and if needed a water sample test- is the best way to check for certain if a flush is required.

Benefits of power flushing

  • Increased efficiency – a clean system will be more efficient and will therefore cost less to run. This could be in the region of 25% more efficient.
  • Your system should heat up faster and should be quieter.
  • Increased system life – Boilers, pumps and radiators all last longer if the system is clean and has the correct level of chemical inhibitor.

Power flushing methods
There are two main ways of flushing a heating system. The first and traditional way is to use high velocity water, but at low pressure to avoid damage to the heating system. The water, along with chemicals are circulated in both directions through the system and boiler. This removes iron oxides, flux and other debris from the system. The water if filtered and replaced with clean water and chemical inhibitor.

The second way is to use a magnetic flushing machine to capture the oxide as it passes through. The machine is connected to the system and chemicals are introduced. This along with agitating the radiators releases the iron oxide. The magnets capture the iron oxide and remove it from the system. The water is neutralised and chemical inhibitor is added to protect the system.

Other options
A system can be chemically cleaned. This involves adding chemicals and running the heating. After a couple of weeks the system is flushed out with clean water and refilled with water and inhibitor. As no machine is used the process can be cheaper but this can be less effective than flushing.

Fitting a magnetic filter. This will capture any loose iron oxide but will not on its own remove build up from radiators or pipes. We would recommend fitting a magnetic filter to a clean system to prevent any problems or the need for flushing in the future.