System Power Flushing
Clean your system to reduce bills and improve the performance of your Heating and Hot Water
What is Power Flushing?
Power flushing is the process of forcing water and a chemical cleaner through your pipework, radiators and boiler in order to break down and remove sludge and scale.
Why might my system need a Power flush?
There a number of reasons to power flush a system and some cases where a power flush is not actually the best course of action however, in many cases the symptoms can indicate both options (as you can see in the two lists below) and therefore an experienced heating engineer should inspect the problem before recommending a Power Flush
Reasons for a power flush:
If your radiators are not getting warm at the bottom then this is most likely caused by a build-up of sludge in the radiator.
Sludge is created as the water in the system breaks down small parts of your pipework and radiators (a bit like rust). These particles travel around your system and settle where the flow of water is at its weakest (the bottom of a radiator).
If some of your radiators are not getting warm, particularly in a specific sections of your home, it could indicate a partial blockage of the pipework with scale and sludge.
If you are having a new boiler installed, most manufacturers strongly recommend the existing system is power flushed to remove and debris and sludge that might impact the performance or life of the new boiler.
A noisy boiler can indicate that the heat generated by the boiler is not being carried away from the boiler quickly enough (so it boils) or the are deposits in the boilers heat exchanger itself causing hot spots in the boiler.
Why a power flush might NOT be needed:
If the top of your radiators are not as hot as the rest of the panel then this is most likely caused by air in the radiator.
Air in your system can be created as a by product of the break down of your system components (that also creates sludge) or by the separation of the air normally found in water as it is repeatedly heated by the boiler.
This air normally ends up at the top of the highest radiator in your system and can be let out by opening the bleed vent on the radiator.
We check this as part of a annual service as it is very common however, if you are having to "bleed" your radiators of air often then there is another underlying problem that needs to be investigated and fixed as air in the system accelerates the creation of sludge and can lead to air blockages.
If some parts of your system or specific radiators never seem to get warm this could be because of partial or total blockage of the pipes leading to the affected radiators. Sometimes a Powerflush might be recommended if there are multiple blockages or it is one of many symptoms however, in some cases the fix could simply be to cut out and replace the blocked section of pipework.
This could also be symptom of an unbalanced system. The normal fix for this is to balance the system, by opening or closing specific radiator valves to control the flow of water around the system as a whole, or it might indicate your pump is undersized, underperforming and about to fail.
A noisy boiler might be because a reduced flow similar to the cause of an unbalanced system above, localised boiling in the boilers heat exchanger because of poor water flow or a blockage in the boiler itself.
We can identify and repair any of these issues whether a Power flush is the right choice or not.
Are there different types of System Flush or alternatives?
Yes, there are three main variations of system flushing:
A Cold Flush
A cold flush should only be used to clear any debris in newly installed pipework or in some cases to help remove a suborn air blockage. It has no effect on blockages caused by sludge or scale.
A cold flush is performed by forcing clean water through the heating system by connecting a hose from the incoming water mains and opening the drain cock to let the water flow through the system.
A Hot Flush
A hot flush is similar to a cold flush and used to be the preferred method of cleaning a system before chemicals and power flush machines became more common and reliable.
Basically, an initial cold flush was performed to remove loose debris then the system was heated with this fresh water (sometime with additional cleaning chemicals) and after a few hours the water in the system was flushed through with mains water again to clear any more debris loosened by the initial flush, hot running and chemicals (if used).
A Power Flush
A power flush is a more involved version of the hot flush as chemicals are added to the system water, sometimes up to a week or two in advance of the actual flush, to break down as much of the debris as possible.
Then a special flushing machine is connected to the system. This machine has a large pump which forces the water through the system at high speed to try and loosen as much debris as possible.
Once the system as a whole has been flushed either the machine will be connected to each individual radiator or all the radiators will be turned off and one turned on at a time to force the high speed flow of water and chemicals through each radiators one at a time.
In some cases the radiators may also be hammered (with a rubber mallet) to loosed the sludge.
The power flush operator may also attach a magnetic cleaner and/or heater to the system to heat the water and capture the metallic elements of the sludge and remove them during the flushing.
Once complete the whole system is flushed through with cold water to remove the debris and chemicals.
After the powerflushing, an additive may be added to neutralise any remaining chemicals (if needed) and final chemical called a system inhibitor is added to help prevent the build of sludge recurring.