What is Power Flushing?
The diagram below shows a typical heating system and problem areas. With modern boilers particularly now with the advent of high efficiency boilers there is a need to ensure your system is clean before installation and treated with inhibiter when commissioning. There is an approved standard required by all manufacturers known as BENCHMARK to which installation must be carried out to ensure your manufacturers guarantee is valid.
All new systems should be pre-commission cleansed in accordance with BS:7593 and Benchmark. This ensures flux residues, excess jointing compounds, mineral oil and other contaminants that can be found in the system following installation, and that can effect the performance of the system or cause component failure, are removed. 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 limescale together with corrosion deposits in the heat exchanger, which could easily have reduced the boiler efficiency by over 5%.
Blockage in radiator valve Leading to incorrect operation of valve, no flow in radiator
- Pump seizure and failure The abrasive and magnetic properties of black oxide sludge increase shaft and bearing wear in pumps causing them to stick or fail.
- Cold spots The familiar cool low central area of a radiator indicates a build-up of black sludge sediment that restricts flow and reduces heat.
- When the top of a radiator is cold during operation, either air or hydrogen is to blame. Hydrogen gas builds up as a by-product of electrolytic corrosion and is flammable (due caution is required).
- Pinhole leak Water damage
- Black sludge in underfloor pipework Reduced flow or blockage in pipework
- Scale (limescale/iron oxides) in boiler Leading to reduced efficiency, increased emissions, higher fuel bills and boiler noise.
Power flushing is the most efficient and effective method of cleansing a central heating system. The principle is to create a powerful fresh water flow under controlled conditions to remove debris from the system. By connecting the power flushing unit to the heating circuit in place of the system pump, boiler or radiator the circuit can be thoroughly cleansed of limescale and corrosion debris. When used in conjunction with a Fernox cleanser a typical power flush can be completed in 3-4 hours.