• Get the best quotes, fast!
  • Over 5,000 engineers across the UK
  • Gas Safe registered engineers

Need a New Boiler?

What work do you require?

Or do you require a boiler repair?

Get THE Best Deal

by quickly comparing 3 FREE quotes

  • Next day installation
  • Quotes from local engineers
  • 1.9 million quotes in 10 years
  • Save up to £500 on installation

The smarter way to find approved heating engineers

Excellent 4.8 out of 5 Trustpilot

Stay Safe.
Always use a Gas Safe registered engineer

What is a Powerflush?

Becky Mckay
By: Becky Mckay
Updated: 19th September 2023

A Powerflush is a cleansing process which aims to remove deposits of sludge, rust and any other debris from your central heating system.

These contaminants, if left, can seriously affect the efficiency of a heating system and, in severe cases, a powerflush could be the only option available. Over time the water in your pipes, boiler and radiators deposits unwanted byproducts like rust. This rust (plus other dirt and debris) becomes an unpleasant, mud-like substance that professionals affectionately refer to as 'sludge'.

Sludge in your heating system can cause to blockages and corrosion which will lead to both inefficiency and/or breakdown. In extreme cases, it can be so damaging that a complete boiler replacement is needed.

If you’re worried your boiler may be on it’s way to breaking down, then we recommend you get a boiler repair. Boiler Guide can help you take the first step by getting multiple reliable quotes to compare.

All of the quotes are for free and come from trustworthy boiler professionals near you. You don’t have to accept any of the quotes you receive, so you have the freedom to choose the best price.

Get your best deal

Quickly compare 3 FREE quotes

  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
Get Quotes Now It only takes 30 seconds
  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
4.6/5 out of 23,524 reviews

1,8 million quotes provided in 10 years

See more reviews:

When is a powerflush needed?

If you carry out regular servicing and maintenance (professional servicing is recommended annually) then a preventative Powerflush should only be necessary every 5-6 years to clear debris and prevent significant blockages from taking hold.

However, this will vary depending on the system you have. For example, some boilers use copper heat exchangers rather than stainless steel which will corrode quicker.

IMPORTANT: If you are planning to replace your boiler it's important that the engineer performs a Powerflush before the installation. Otherwise, you risk contaminating the new boiler with damaging sludge and debris that's hanging around in the old pipework.

Signs it’s time for a powerflush

There are signs to look out for that suggest that all is not well in your central heating system.

  • Cold areas on radiators e.g. at the bottom
  • Excessive noise from the boiler or the heating system pump
  • Discoloured water when you bleed the radiators
  • Heating is slow to warm up
  • Cloudy tap water (limescale in system)
  • Some radiators struggle to heat up as well as others
  • Radiators cold but pipes are hot
  • Boiler regularly shuts down and needs restarting
  • No water escapes when you bleed a radiator
  • Noisy radiators and or / boiler
  • Small leaks in radiators.

Find out how to keep the levels of sludge in your heating system to a minimum in Water Treatment in Heating Systems.

If any of these problems sound familiar to you, it's time to contact a professional engineer. While a Powerflush may be all that is required to get your heating back on track, unfortunately it’s not always that simple. A system may be so damaged that it is actually cheaper to replace rather than repair. If that's the case, you’ll need to consult with at least two professionals to make sure you're getting the right solution at the best price. Use our service to get free boiler quotes from up to 3 trusted engineers in your area.

How does a powerflush work?

An engineer will connect a pump to your central heating system. If it's a combi it will be connected at the pump head but if it's a system boiler it will be connected at the circulation pump. This pump will push special chemicals through the pipes, boiler and radiators.

This includes a chemical that will remove sludge and rust, a descaler to remove limescale and corrosion inhibitor to help prevent future rust from forming. The engineer will collect and dispose of any contaminated water, debris or particles that they remove from the system.

The engineer may also use special tools on the exterior of the radiator to dislodge stubborn blockages. They should be able to measure the temperature of your radiators before they have started work and then show you the improvement after the Powerflush.

The whole process can last anything from 6 – 10 hours depending on the number of radiators in your home, the age of the system and the severity of the sludge in the system. The engineer may find more problems than originally anticipated such as needing new parts to replace those that have been damaged beyond repair. Most Powerflush jobs can be completed in one day but some of the more severe cases may require longer.

A qualified engineer will be able to perform repairs, replacements and carry out a Powerflush.

Benefits of a powerflush

It's not all doom and gloom; there are lots of positive reasons to get a Powerflush carried out too.

  • Radiators will heat up quicker
  • Radiators will get hotter
  • Quieter radiators / boiler
  • More energy efficient system = cheaper energy bills
  • Higher hot water temperatures
  • More reliable i.e. less chance of breakdown
  • Increase the life of your heating system.

Who can carry out a powerflush?

Not all companies will perform a Powerflush to the same standard. There are a range of chemicals and equipment on the market and, as with all industries, there are providers with varying levels of expertise and attention to detail. Always check independent review sites and request customer recommendations. We recommend sourcing at least two quotes from professionals so you can compare costs.

Boiler Guide has a network of 5,000 reputable engineers across the UK and can provide you with up to 3 free of charge, no obligation, competitive quotes. Each quote is tailored to your own heating situation so that you can secure the most accurate and deal.

You can start getting quotes for boiler repairs for free and without obligation by clicking the button below. You’ll fill in a short form and we’ll contact you quickly with all the information you need.

Get your best deal

Quickly compare 3 FREE quotes

  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
Get Quotes Now It only takes 30 seconds
  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
4.6/5 out of 23,524 reviews

1,8 million quotes provided in 10 years

See more reviews:

Do you need a professional?

It’s best to hire somebody who knows what they’re doing.

While there are Powerflushing kits for hire and instructional videos available on the internet, it's a risky and complicated job. A professional will make a Powerflush look easy, clean and safe but the reality is it's a job that has the potential to get very messy. Specialist chemicals and equipment should only be handled by those trained to do so.

It's also possible that carrying out the work on your heating system by yourself may invalidate any manufacturer's warranty you have. A professional engineer will provide you with a certificate to prove that the Powerflush has been carried out. This is crucial if you need to evidence to a manufacturer or insurance provider that you have had all work carried out by a professional.

Finally, if the work is completed incorrectly it could cause more damage than you had to begin with.

NOTE: Installing a magnetic filter will not deliver the same benefits as a Powerflush procedure, but it can protect a system (that is still working well) from future sludge blockages.

Powerflush costs

There are lots of factors that will affect the price of a Powerflush such as size and complexity of the heating system, not to mention any incidental troubleshooting that crops up. A Powerflush can cost anything between £300 to £1000+ but will also vary from engineer to engineer. Sometimes there will be additional costs like extra descaler chemicals or replacing the TRVs.

It’s important that your central heating system is as efficient as it can be at all times and, although a Powerflush can be an expensive process, it can also save a lot of money over time in reduced heating bills.

Is a powerflush always the solution?

In some particularly severe cases, you may find that it’s actually more cost-effective to replace the system than carry out a Powerflush. A Powerflush will not fix broken parts. If a blockage has caused a part to break that will add time and cost to the job to get the system back to optimum performance. A professional will be able to advise you if this is the case.

At Boiler Guide, we recommend sourcing and comparing multiple quotes to find the best quote for you. Luckily, we can help you with that. We have a network of trustworthy and vetted heating engineers across the country who can offer you quotes. You can get up to 3 free quotes from different installers for free and without obligation. They’ll also be able to help advise you on if a powerflush or a new boiler is the right move for your boiler.

We recommend getting multiple quotes so that you’re able to compare them. This reduces the risk of overpaying and helps you secure the best deal. Are you ready to take the next step so that you can have a highly efficient boiler again? Just click the button below to get started.

Get your best deal

Quickly compare 3 FREE quotes

  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
Get Quotes Now It only takes 30 seconds
  • Quotes from local engineers
  • Get quotes today, installed tomorrow
  • Finance options available
  • Save up to £500 on installation
4.6/5 out of 23,524 reviews

1,8 million quotes provided in 10 years

See more reviews:

Becky Mckay

About the author

Becky Mckay

Becky has been a writer at Boiler Guide since 2021. Her vast boiler knowledge means she’s ready to help with any home heating query, big or small!

Need a New Boiler?

What work do you require?

Or do you require a boiler repair?

Get THE Best Deal

by quickly comparing 3 FREE quotes

  • Next day installation
  • Quotes from local engineers
  • 1.9 million quotes in 10 years
  • Save up to £500 on installation

The smarter way to find approved heating engineers

Excellent 4.8 out of 5 Trustpilot

Stay Safe.
Always use a Gas Safe registered engineer

Find local heating engineers

Find approved boiler engineers
in your area.

Begin your search by entering your postcode below.