Power flushing is the term used for cleaning a central heating system of sludge and debris, with a powerful flushing machine and chemicals.
This sludge can reduce water flow to the radiators, causing it to be cold spots, it can also cause blockage in the pumps,it can cause corrosion in the central heating system.( see diagram bellow )
This can lead to shorten the life span of your boiler and the central heating system.
Power flushing is necessary to keep your system in top condition and even help extend the life of your boiler , it can also help minimise breakdowns and repairs.