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Power Flushing v MagnaCleanse

Power flushing vs Magnacleansing

So, you’ve noticed your house doesn’t get as warm as it used to, and the cost of heating it has increased. Does your system need to be cleaned to restore efficiency?

Or you have a new boiler installed. It is prudent to clean a heating system immediately before fitting a new boiler to an existing system to prevent possible future problems. Indeed, boiler manufacturers insist on it to provide long-term warranties. Many systems contain corrosion and sludge, even if no flow problems have yet shown themselves.

Existing debris can be mobilised by alterations to the system/piping and the increased efficiency of the new boiler. This debris may then accumulate in the boiler heat exchanger, causing noisy operation, reduced efficiency and, in extreme circumstances, boiler failure.

Why do I need a system flush?

After many years of circulating through the system, the water will be contaminated with rust and magnetite. Over time the rust and debris will turn into a sludge-like substance that will settle in the radiators and pipework, making the system inefficient and prone to component failure!

What are the symptoms of a system in need of cleaning?

  • High heating bills
  • Noisy boiler/heating system
  • Radiators have cold spots
  • The system slow to warm up
  • Radiators need regular bleeding
  • Pump failures
  • Evidence of sludge and rust in the header tank


What are the benefits of having my heating system cleaned?

  • Lower heating bills – save up to 25%
  • Faster heat-up times
  • The entire surface of radiators heating your home
  • Extended lifespan of heating system
  • Better circulation and a quieter system

In addition, the high efficiency and compactness of modern boilers, developed to minimise fuel costs and pollution, means they are more susceptible to problems caused by water debris in the system. In both cases, cleaning the system (then regularly checking the inhibitor levels) will keep your boiler and system healthy and efficient over its lifetime.

What sort of flush does my system need?

There are two main ways of cleaning the system, well actually three, but one is so ineffectual as not to count. Power flushing, a Magnacleanse or just a chemical flush. All three methods meet the British standard for the treatment of hot water in domestic central heating systems, BS7593: 2006

Clean and flush using gravity

A chemical flush is the most basic option to meet the standard. Cleansing chemicals are added to the system and circulated during regular operation of the heating system; a minimum of 48 hours is recommended. After the treatment, the system is drained and refilled with fresh water treated with scale and corrosion inhibitor. Due to the reliance on only the chemicals to break down any settled sludge and debris, this option is entry-level at best. It can’t be guaranteed to clean the system and restore efficiency effectively.

What is a Magnacleanse Flush

A Magnacleanse system flush can remove even hardened debris. The system circulates cleansing chemicals around it using the boiler and pump.

The magnetic filter is connected to the system before the system water enters the boiler, trapping any dislodged sludge deposits before they can enter the boiler and be easily disposed of.

Each radiator is flushed individually and further agitated using a vibrating tool attached to an SDS drill to ensure as much sludge can be dislodged as possible.

Even hardened debris is shifted, reducing the need to remove radiators to clean the system completely.


What is power flushing?

Some things you can’t shift with magnets alone…

Central heating power flushing has been around since 1992 and is the benchmark for system cleansing. A purpose-designed power flushing pumping unit is fitted into the system, which is then forcibly cleansed using water and treated with cleaning chemicals at high velocity but low pressure so that no physical damage is caused to the system. An electric heater can be connected to the power flushing unit so effective cleaning can be carried out without using the boiler as a heat source. This means that even if your boiler has failed, the system can be thoroughly cleaned and efficiency restored before fitting your new boiler. A magnetic filter is also connected to the flushing unit, ensuring the maximum amount of sludge is mobilised and removed.

The powerful flow, combined with an instantaneous flow reverser device and vibrating tool, will dislodge and mobilise deposits and corrosion that resist other traditional system cleaning methods. Once the corrosion and sludge deposits have been loosened and mobilised, fresh, clean water is forced through the heating system, pushing the contaminated water out through a full-bore dump valve to waste. During the power flushing process, radiators are individually flushed without removing or disconnecting them from the system, directing the entire pump output through each radiator separately.

How will you know what sort of flush I need?

During the survey of your heating system, we will inspect each radiator, in turn, using our sophisticated infrared camera. This will show the temperature each radiator is heating up to and any build-up of sludge and cold spots in your radiators.

The radiators are also inspected after cleaning to provide a visual record. We can then advise if a Magnacleanse is sufficient or if a complete power flush will be required.

If you are replacing a combination boiler and your system is sealed and hasn’t needed the pressure constantly topping up, a Magnacleanse is usually adequate.

Suppose you change the system from a traditional open vent system to a modern sealed system, or the system is contaminated and inefficient. In that case, you will usually need a complete power flush.


How long does cleaning take?

Carrying out a full power flush on a heavily contaminated system will usually take a whole day, but the results will be worth the wait. The time required will depend on the following:

  • The number of radiators you have in your home.
  • How old your current system is.
  • The amount of sludge and debris built up.

A Magnacleanse can be carried out while your new boiler is set up and commissioned. Our team will carry out the cleaning process as part of the installation process, usually in a few hours.

System protection and water treatment 

After cleaning your heating system, we ensure it stays in tip-top condition by treating it with chemical scale and corrosion inhibitors. After a power flush, we will provide a comprehensive certificate recording the system details before and after flushing, including:

  • The type, age, and condition of the system
  • What system components are installed
  • The number of radiators and what they are made of.
  • The system pipework
  • The total dissolved solids (TDS) in the system water both before and after flushing
  • The radiator temperatures both before and after cleaning

Article by Jared Hooper MIPHE RP

Company Founder, Member of the Chartered Institute of Plumbing and Heating Engineering, a Gas Safe and OFTEC registered Plumbing and Heating Engineer with over 30 years experience.