Plumbing and Heating Power Flushing
A G Brown & Son
Question and answer on Professional Chemical power flushing
What is a power flush?
- Power flushing is the most efficient and effective method of cleansing a central heating system. The principle is to circulate a cleansing chemical and water mixture under controlled conditions to remove debris from the system. The chemical cleaning water has a high flow rate but not much pressure, so your existing pipework remains quite safe. By connecting the power-flushing pump to the heating circuit in place of the central heating system pump, boiler or radiator the circuit can be thoroughly cleaned of lime scale and corrosion debris.
What symptoms indicate that power flushing would be Beneficial?
- Radiator water black with Iron oxide sludge
- Heating system slow to warm up
- Cold spots in the middle of the radiators
- Unpleasant boiler noises
- Repeated pump failure
- Radiators need frequent bleeding
- Leaking radiators from pin holing in the radiator body.
Power flushing will clean a central heating system internally improving radiator performance and heat output.
What happens during a power flush?
- The power-flushing pump is simply connected into the heating system. Either across the standard circulator pump couplings, across the tails of one radiator, or wherever most practicable.
- Power flushing is a highly effective cleansing operation, which works by pumping water at a much higher velocity than usual through the heating system, to loosen and mobilise harmful corrosion deposits, and to suspend them in the rapidly moving water. The process is made more effective by specialist cleansing chemicals, and an instantaneous flow reversal device, which creates turbulence in the radiators to optimise "Pick Up "of the debris.
- Once loosened, the unwanted debris is purged from the system with clean water. At the end of the flushing process, the system contains fresh clean water, and reinstatement of the system to normal operation takes only a few minutes.
- During the process, radiators are individually flushed, without removing or disconnecting them from the system, by directing the full output of the pump through each radiator separately.
- Power flushing is not a high-pressure operation, and it is suitable for most domestic wet central heating systems. It is carried out with minimal disturbance and disruption to the normal operations of the system. Often without disconnecting the boiler or any radiators.
What are the benefits of a heating system power flush?
- Cures flow and circulation problems
- Restores system efficiency
- Restores heat output to radiators
- Cleans the whole system, including under floor pipe work.
- Removes aggressive water; treatment prevents further corrosion.
- Cures or prevents boiler noise
- Power flushing and descaling in only one visit
- Complete process carried out in a day or less
- More effective than traditional flushing methods
- Minimises boiler warranty problems
I am having a new boiler installed; do I need a power-flush?
- The high efficiency and compactness of the heat exchangers on modern condensing boilers
- (Developed to minimise fuel costs and pollution) makes them more susceptible to problems caused by debris in the system water. Boiler manufactures insist that heating systems must be thoroughly flushed before installing a new boiler.
- It is important when installing new boilers into old systems that all sludge is first removed from the system or this could accumulate in the new boiler and lead to premature failure. Additionally, in hard water areas existing systems will have accumulated lime scale together with corrosion deposits in the heat exchanger, which could easily have reduced the boiler efficiency by over 5%.
- All new systems should be pre-commission cleansed. This ensures flux residues, excess jointing compounds, mineral oil and other contaminants that can be found in the system following installation, and this can affect the performance of the system or cause component failure, are removed.
Can Microbore systems be power flushed?
- Yes, they can, but the flow rates will be greatly reduced and so the flush may not achieve the same results as with a 'normal' larger bore system. A microbore system is a heating system that uses pipe work smaller than 15mm. In the UK, this is normally 8mm or 10mm. Microbore systems are more prone to circulation problems and blockages.
Are there any problems with doing a power flush?
- The success of a power flush will depend on the level of heating system corrosion, which has occurred before hand. The process will cure most circulation problems, but cannot undo the corrosion and gradual decay that has led to the need to power flush the system.
- Whilst it is rare for a heating system to experience leaks after the power flushing process, it is not possible to inspect a system internally beforehand, and the need to use a flushing and dispersing chemical for effective cleansing means that occasionally we may find a leak
- The advanced stage of corrosion required for such a situation means that the leak would occur imminently even without a power flush. We believe that it is better that it occurs whilst we are present to remedy the problem, rather than for it to arise over a weekend or whilst the house is unoccupied.
- Systems which have been neglected over a period of time, or have not been treated with an effective corrosion inhibitor, may have severely compacted corrosion debris, in the pipe work, radiators, or boiler, and it is possible even after the power flush, some radiators may still not be effective, or boilers on the margin of failure may cease working due to sludge and debris later breaking lose and collecting in the heat exchanger.
What type of heating system do I have, is it suitable?
- Virtually all older central heating systems are suitable for power flushing. If you are having a new boiler installed you will have to have the system power flushed.