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What is a Powerflush?

A powerflush is essentially a deep clean of your central heating system and a procedure that removes the build-up of dirt, sludge and rust from your boiler, pipes and radiators. Your system can accumulate debris over time and, if left untreated, can lead to blockages or corrosion and reduce your boiler’s efficiency. A clogged system can also result in boiler breakdowns and problems with your radiators.  

Powerflushing is a fast and effective way to flush your system and helps improve efficiency, prevent boiler breakdowns and increase the lifespan of your heating system. 

When should you get a powerflush?

A powerflush is a must every five to six years if a professional checks your system regularly unless your system develops a build-up of rust, sludge and other debris sooner. You should arrange an annual service anyway to ensure your system remains safe and operates correctly, plus it helps to keep your boiler warranty valid. 

If you’re getting a new boiler installed, your heating engineer will likely recommend a powerflush before installing it to remove sludge and debris from your system. 

Warning signs your system requires a powerflush

The common signs that show your central heating system needs a powerflush are as follows:

  • Cold patches on your radiators, particularly if they’re at the bottom
  • Central heating takes a while to heat up
  • Your radiators require constant bleeding
  • Noise coming from your boiler and radiators
  • Some radiators struggle to heat up
  • Discoloured water when bleeding your radiators
  • No water comes out when bleeding your radiators
  • Pipes are hot, but radiators are cold
  • Your boiler keeps shutting down and needs restarting
  • Leaks in radiators

When sludge and debris clog your system, it can cause the above issues and lead to severe damage or breakdowns. If you’re experiencing any of these problems, contact a qualified heating engineer right away to inspect your central heating system. 

The best-case scenario is that your engineer tells you that your system needs a powerflush, but they may say the underlying issue is something other than a build-up of sludge and debris.  

What happens during a powerflush?

If you require a powerflush, a qualified heating engineer will need to connect a specialised machine to your central heating system. This machine connects to the pump head if you have a combi boiler or the circulation pump if you own a system boiler. 

Once attached, the machine uses a lot of pressure to push a blend of chemicals through your boiler, pipes and radiators to dislodge rust, sludge and debris in your system. The mix of chemicals includes a descaler to remove limescale and a corrosion inhibitor to prevent rust from reoccurring. 

After removing the rust, sludge and debris, your engineer will dispose of any contaminated liquid and particles.  

How long does a powerflush take?

It depends on the size of your central heating system, how much sludge is clogging it and whether any parts need replacing. The average time it takes to complete a powerflush is 8 hours, but it can take up to 2 days if you have a complicated system. 

If your engineer finds any other problems or has to replace parts, the powerflush can be a lengthy process and take much longer than the average job. 

Who can perform a powerflush?

You must always ask a qualified heating engineer to perform a powerflush or other work on your central heating system. The Gas Safe Register is the official list of businesses legally permitted to carry out gas work, so be sure to check the list before contacting an engineer. You can also check their Gas Safe ID card to see what types of gas work they are qualified to do.  

If you’re unsure which company to choose, you can check independent review sites to see what other customers say about their experiences. We also recommend getting quotes from different companies to compare costs and find the best deal. 

How much does a powerflush cost?

The cost of a powerflush will depend on the size of your central heating system and the complexity of the job. Powerflush costs also vary from one company to the next, which is why we always recommend getting quotes from different engineers.

Prices for a powerflush start at around £300. You may think that seems expensive, but getting a central heating powerflush every five or six years will help keep your boiler running efficiently and prevent costly repairs and breakdowns. 

The benefits of powerflushing your system

Getting a qualified engineer to powerflush your system has significant benefits, such as:

  • More reliable central heating system
  • Helps extend the life of your boiler
  • Reduces noise from your boiler and radiators
  • Radiators get warm quicker 
  • Improves energy efficiency of your system
  • Prevents boiler breakdowns
  • Improves the quality of your heating and hot water

Is a powerflush worth the money?

Absolutely. Powerflushing your system has many benefits for not only your home but your wallet as well. However, if your engineer discovers severe damage and tells you that some parts need replacing, they may say it’s more cost-effective to replace your system rather than carry out a powerflush and repairs.