What Is A Powerflush
What is a Powerflush?
Quite often the first you'll ever here of a powerflush is when your heating or boiler is broken. A gas engineer will tell you that the pump has failed or the reason why your radiators don't heat up is because of a build up of sludge in your heating system. The moajority of heating systems use a pump to circulate water around the boiler and around the radiators.
Sludge Build up
When the heating system is filled with water for the first time, it is mains water which is used. This water, although great for drinking, isn't so great for heating systems. It is good quality clean water, but it contains lots of air. After a few cycles of being heated and then cooled the air is often expelled and collects at the top of the system. It can some times be removed by automatic air vents in the boiler but it can also be removed by bleeding the radiators (check this page for a guide to bleeding radiators).
Air in the Heating System
The air and water in your heating system react with the different metals and cause corrosion. In a normal heating system there will be at least three or four different metals; copper, tin, iron, aluminium, chrome, nickel are all in the average system. These metals react not only with the water but also with each other in whats called galvanic corrosion. If the water is then sealed in a pressurised system there won't be much of a problem, especially if no more water is lost or added and if a chemical inhibitor is used to retard any further corrosion.
Loss of Pressure in a heating System
Most heating systems will loss water and pressure over time and more water needs to be added to the system to keep the correct pressure. This is the cause of build up of sludge and corrosion in a heating system. As more water is added the metals and air react to cause more corrosion. The corrosion takes the form of small particles, some are like rust but others are black and they are called magnetite. This sludge is heavy and quite often sinks to the bottom of your system when its turned off. Unfortunately draining the system will not remove this as the water just washes over it. Another problem is that over time the corrosion becomes 'baked'; hard blockages which stop the water flow. These are quite often the first symptoms which materialise in a heating system. They show up as cold spots on the lower part of the radiators.
Reason Why a Powerflush is Essential
A powerflush is a procedure which uses a large powerful pump attached to a sump of water. The pump forces water around the system often with a special chemical which breaks up the hardened corrosion. It is attached to the boiler or through a radiator. We use a component which is connected into the system and contains a powerful magnet. This device catches the magnetite as it passes through and means less water is used in flushing out the debris. Other devices can be added to heat the water which aids the removal process. It normally only takes one day (depending on the amount of sludge and the number of radiators). the chemicals are added to the sump and forced round hte system by the pump. each radiator is opened individually to ensure the full flow goes through, a special hammer can be attached to a rotary drill which vibrates the base of the radiator helping remove solid deposits. Once all the radiators have been flushed the filthy water can be dumped and replaced with clean water. This process continues until the system water is as clear as tap water. The final procedure is to add inhibitor to stop corrosion happening in the future. Some systems are more prone to corrosion than others, if your system is a open vented system then it will be prone to corrosion, as will systems which need topping up frequently.