British Gas Powerflush

A British Gas Powerflush will improve your central heating system, help you use less energy and keep you warm at home. It comes with a lifetime guarantee.[2]

Everything you need to know about a Powerflush

Watch our short video on British Gas Powerflush to find out more about what it is and why you might need one

Why you may need a Powerflush

A Powerflush helps deal with heating problems that you can't always see

A diagram of a pipe blocked with sludge, rust and limescale.

Sludge, rust and limescale causes leaks and blocked pipes

Dirty water in your pipes causes heating problems and reduces efficiency.

A diagram of a radiator blocked with sludge, causing cold spots and inefficient heat flow.

Sludge build-up causes cold spots in your radiators

This means they have to work harder to heat a room and you waste more energy.

A diagram of a boiler with a red warning sign.

A clogged boiler and pump causes breakdowns

87% of boiler breakdowns are due to dirty water in your heating system.

How does a Powerflush work?

A diagram of a radiator blocked with sludge, causing cold spots and inefficient heat flow.

Before a Powerflush

The sludge in your radiators creates cold spots so the heat can't flow around them effectively.

A diagram of a radiator being cleansed by a British Gas Powerflush, which is removing the sludge and replacing it with clean water and protective chemicals.

During a Powerflush

We'll use a machine and three-step chemical process to thoroughly clean out your boiler, pipes and radiators, and replace dirty sludge with clean water.

A diagram of an efficient, warm radiator, with no cold spots and correct heat flow.

After a Powerflush

After the Powerflush has removed sludge from your pipes, radiators and boiler, your system should work much better.

Powerflush savings and efficiency

A Powerflush helps prolong the life of your system, lower your bills and reduce the risk of breakdowns.

  • Helps your home heat up faster
  • Wastes less energy, which saves you money
  • Reduces system wear and tear
  • Helps to protect your boiler
  • Lifetime guarantee for all Powerflush customers, provided you have an existing and ongoing HomeCare contract[2]

How to book your Powerflush

A photo of a British Gas call centre agent, smiling as she talks to a customer over the phone.

Step one

Book a free appointment and one of our engineers will pop over and check your central heating system, then provide a fixed-price quote.

A photo of British Gas engineer, smiling as he takes his tools of out his bag.

Step two

If you decide to go ahead with a Powerflush, we'll help you book an appointment. It can take around eight hours to complete a Powerflush.

A photo of the same British Gas engineer as in the previous photo, laughing with a customer as they examine a boiler together.

Step three

We offer a lifetime guarantee for all Powerflush customers, provided they have an existing and ongoing HomeCare contract. Read our T&Cs for more details.

Need to know more?

The price will depend on the size and number of radiators in your home. Contact British Gas for a no obligation quote. We offer a number of easy ways to pay for a Powerflush, including instalments

What’s included in a Powerflush:

  • Lifetime guarantee – Your British Gas Powerflush is guaranteed for life as long as you remain on an existing and ongoing HomeCare contract. This means that we’ll re-flush your system for free as many times as you need it in the future. Each radiator is isolated and flushed individually
  • Each radiator is isolated and flushed individually
  • A full system drain down, de-sludge with a chemical inhibitor added afterwards to prevent future build-up
  • A British Gas engineer completing fixed-price work
  • Read our terms and conditions for more details
  • Check for cold spots on your radiators by feeling the bottom of them. If they're cooler at the bottom than at the top, you may have a blocked radiator with sludge inside it. A Powerflush will remove the sludge and make your radiators hotter and more efficient
  • If your heating or hot water is slow to heat up or it's not feeling as hot as usual, your system may be blocked
  • If you have an old boiler, or one that hasn’t been serviced for a number of years, it may be inefficient or blocked. A qualified gas engineer will confirm this for you. Contact British Gas for an Annual Boiler Service
  • If you have old pipework or radiators, they may be rusting and causing a build-up of sludge in your heating system
  • If you have a new boiler, it is important that all sludge is removed from the system, or this could clog up your new boiler, making it less efficient and leading to future breakdowns. Your engineer will check your boiler efficiency during your Annual Boiler Service
  • Most of our Powerflushes take a full-day appointment that lasts around eight hours
  • Our engineers will tell you when they are working out your quote. It will depend on the size of your home, how many radiators you have and how blocked or dirty your current heating system is
  • It improves the circulation of water within your system and makes it more efficient. Your radiators will heat more quickly
  • It'll reduce the risk of breakdowns, cold radiators and noisy boilers
  • It'll help prolong the life of your boiler, radiators and systems
  • We'll use a machine and three step chemical process to thoroughly clean out your boiler, pipes and radiators, and replace dirty sludge with clean water using a cleansing agent. We'll need to drain the heating system down and flush every radiator individually. We can then get rid of the waste down a suitable outside drain

We’ll arrange for an engineer to check your heating system is suitable for a Powerflush. The following systems can't be Powerflushed:

  • Electrical heating systems
  • Twin-entry radiator valves
  • Pipes of less than 15mm in diameter

Powerflush is not included in any of our HomeCare packages. However, if you buy a British Gas Powerflush, it comes with a Lifetime Guarantee, as long as you have an existing and ongoing Homecare contract that covers your central heating system. This means we’ll re-flush your system for free as many times as you need it in the future.

Related products

Radiators

Don't forget about your radiators - they're just as important as your boiler in keeping your home warm.

System filters

Prevent sludge and debris from clogging up your heating system ensuring your boiler is working quietly and efficiently

Radiator Valves (TRVs)

Control the temperature in each room and save money by only using the energy you need

Thermostats

Control the temperature without having to worry, so you're never too hot or too cold at home

  1. Monday to Saturday: 8am - 6pm, Sunday: Closed. We may record calls to help improve our service to you. Calls to 0330/0333 numbers will cost you no more than 01 or 02 numbers from landlines and mobiles. If you get 'inclusive minutes' with your package, calls to 0330/0333 numbers will be part of these.

  2. Your Powerflush comes with a Lifetime Guarantee, provided you have an existing and ongoing Homecare contract that covers your central heating system.