Image of a power flush unit placed behind a signwritten GMS van

A power flush is the process used to remove build-up of sludge and debris in your central heating system. During a flush, water is sent through the pipes and radiators under high pressure to dislodge the residue and improve the efficiency of the system, as well as increasing the lifespan of your central heating.

Power flushing should be completed on a semi-regular schedule and as part of your maintenance; most experts recommend that you have a power flush performed every five to ten years. This, alongside your annual boiler service and completing any repairs in a timely manner will help ensure that your central heating system operates efficiently and is less likely to develop faults.

What to expect from a power flush?

A professional engineer should complete your power flush. Our team are experts in ensuring that your boiler is working efficiently and that your home remains cosy, all while keeping costs at a minimum.

When the engineer turns up to complete your power flush, they will follow the below procedure.

  • Set up of equipment. The engineer will use a ‘power station’ that comprises a number of hoses and a powerful unit that pushes water through the system at a high velocity, forcing the debris and sludge out.
  • The first hour and a half or so will be when the engineer completes the initial flush, using water and going in both directions.
  • Following this, they will then focus on any areas that are more difficult, especially the radiators that might be completely blocked.
  • If there are particularly heavy deposits, the engineer might use an ‘agitator’. This is a tough pad attached to a hammer action drill.
  • Once the engineer is satisfied that the flush has been successful, they will add a chemical neutralizer that will be flushed through, before testing the pH of the water. This is to ensure that it is not too acidic, as this can cause corrosion.
  • The final stage is the introduction of an inhibitor chemical, which is specifically chosen to prevent corrosion and help reduce sludgy build-up in the future.

Depending on the size of the property, the number of radiators, and the initial condition of the system, this process can take anything from a few hours to a full day.

Signs you might need a power flush.

While it is recommended to get a power flush every five years or so, you may notice some signs that you should organize one sooner. These include:

  • Cold strips at the bottom of the radiators, or only a small amount of heat at the top.
  • Black water in the system – you might notice this if you remove a radiator or need to get any repairs completed. This can also be seen if you are bleeding your radiators.
  • The radiators are struggling to heat or remain cold even though the pipes are hot.
  • The system seems to be working less efficiently.
  • Overflowing attic header tank.

It is also a good idea to get a flush done if you are getting a new boiler but keeping the existing radiators and pipework. Most installation teams will compete a ‘dynamic flush’ at the time of fitting, using just pressured mains water, but your engineer might suggest a power flush to get it as clean as possible.

When a power flush might not be the answer.

Although power flushing is an effective way to improve efficiency and make sure that your system is functioning as well as it can, it is not always the best idea.

For example, if you have anything that is broken in your system, like valves, then the pressure used in the power flush could cause more issues. It can also cause leaks by putting too much pressure on weak areas.

If you are struggling with low pressure errors or the boiler is failing to fire up, this could mean a simple repressuring job – or it could indicate a leak somewhere.

The other thing to consider is the age of the central heating system. A power flush is not going to give a new lease of life to older systems; it will be much more cost effective in the long run to replace the boiler, pipework, and radiators, even if you do it in stages.

Get the experts in to complete your power flush.

While there are some things that you can do yourself to help maintain the efficiency of your central heating system, a power flush needs to be completed by a Gas Safe engineer – and the team at GMS are experts.

Speak to us today to schedule both your annual service and your power flush and let us help you keep warm and cosy this winter without breaking the bank.