Without treatment, corrosion debris will accumulate in the boiler causing increasing limescale deposits, reduced heat transfer and up to a third of a fuel bill going to complete waste.
This increases in frequency and intensity as deposits of sludge and scale build up in an unprotected boiler.
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).
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.
The objective is to restore systems with circulation and boiler noise problems (caused by sludge and corrosion deposits) to optimum operation. Power flushing removes these deposits and the problems that they cause.
It is prudent to power flush a heating system immediately before fitting a new boiler to an existing system to remove excess flux, swarf and other debris and the grease / oil used to prevent rusting of components before use, thus preventing 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.