Power Flushing is a process where central heating systems are cleaned using low pressure (so as to not cause damage to the system), but high velocity water.
You should consider a Power Flush from NJS Installs if your central heating system suffers from system noise caused by compacted debris (sludge) and corrosion. If you find cold spots on radiators, excessive radiator bleeding is required, or strange noises coming from boiler, these could all indicate that a Power Flush is required. See this handy leaflet from Kamco
It is good practice to flush a heating system immediately before fitting a new boiler to an existing system to prevent possible future problems. Many systems are found to contain corrosion and sludge, even if no flow problems have yet shown themselves.
Existing debris is often mobilised by alterations to the system/piping and the increased efficiency of the new boiler, and may then accumulate in the boiler heat exchanger, causing noisy operation, reduced efficiency and, in extreme circumstances, failure of the boiler. The high efficiency and compactness of modern boilers, developed to minimise fuel costs and pollution, means that they are more susceptible to problems caused by debris in the system water.
The power flushing pump is simply connected into the heating system, either across standard circulator pump couplings, across the tails of one radiator, or wherever most practical. The powerful flow, will dislodge and mobilise deposits and corrosion which resist traditional system cleaning methods.
System flushing will not fix design or mechanical faults, which should be rectified, but in many cases it will cure the problems caused by these.