Power Flushing: What Is It and Does My Central Heating System Need It?

power flushing can improve the efficiency of your central heating

A power flush is a procedure that is designed to clean your central heating system, by removing any sludge, rust or debris that may have built up over time.

80% of boiler and central heating problems are caused by sludge buildup in the system, so power flushing can help to prevent boiler breakdowns and related maintenance costs.

WARNING: You should never attempt to power flush your system yourself, as this could cause considerable damage to your central heating apparatus.


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Why Might My Central Heating System Need Power Flushing?

Your central heating system may require a power flush if you are experiencing some or all of the following problems:

  • Radiators that leak discoloured water when you bleed them.
  • Radiators that still have cold spots after you bleed them.
  • Radiators that are slow to heat up, or don’t reach a high temperature.
  • Noisy boilers or central heating pumps. 

It is also recommended that you power flush your system before you have a new boiler fitted, to make sure that all debris is removed from the system.

WARNING: Many boiler warranties state that your policy will be void unless the system is power flushed before the boiler is installed, as any lingering rust or particles can damage the boiler and block the filters.

How Does Power Flushing Work?  

Power flushing is a fairly simple procedure:

  1. The heating engineer will attach a high flow, low pressure pump to your central heating system.
  2. A cleaning solution is then pushed through the system to flush out any rust, sludge or debris. The solution usually contains a light acid-based chemical, as well as a descaler which can help to remove any limescale buildup.
  3. A rust inhibitor should then be pumped into the central heating system to help prevent further build-up. Some companies charge extra for this, so check if it is included in your quote before you book the service.
  1. After the process is complete, your central heating system will be flushed with clean water. The engineer will test a sample of the water to make sure that there is no acid left in the system.  

IMPORTANT: Power flushing may not be suitable for microbore systems or open vented systems. In these cases ‘powder flushing’ is usually more effective for removing debris. 

How Long Does a Power Flush Take?

On average, a routine power flushing service takes between 4 and 6 hours, however, this can differ depending on the size of your central heating system and the amount of rust or sludge present.

How Much Does Power Flushing Cost?

Again, this will depend on the size of your central heating system and the amount of work required. Most companies quote a starting price of £350, but it is not unheard of for power flushing to cost more than £1,200. You should be wary of insurance companies that offer a power flush service attached to an insurance policy, as they may charge a lot more for the service than an engineer would.

Who Can Carry out a Power Flush?

You should always use a qualified heating engineer or heating company to carry out a power flush. When choosing an engineer, check that they have insurance that will cover any damages that may occur if any problems arise during the service.        

You can find further information on power flushing at The Power Flush Association website, or ask a qualified engineer during your annual boiler service.


Problems with Your System? Book a Boiler Service!

If you’re experiencing problems with your central heating system, the best thing to do is to book a boiler service with a qualified engineer.

Simply click below or contact our team on 0800 080 7875 to get free, instant service quotes from qualified engineers in your local area now.


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