If the water in your heating system is mud like or black in colour, your system water is badly contaminated. This is Iron Oxide sludge.
As the water in the system ages natural chemical processes occur and particals are produced, The particals and chemicals are produced from internal rusting of steel radiators, the use different metals in your system, debris from installation etc. If left for long periods of time the particals and chemicals increase and the rate at which they are produced increases, forming a sludge, during this process from a liquid to a semi solid a gas is also produced called Hydrogen. If you need to bleed your radiators frequently and a gas smell is apparent when you bleed them, then your system is badly contaminated.
As the circulating pump in most domestic heating systems is low velocity/low pressure, most of the particals in the water do not travel very far from their source and consequently are deposited in the nearby pipework and radiators. This process is happening all around your system and so deposits are usually found at the bottom of radiators, low level pipework, boilers etc. If you have radiators that are cold at the bottom or have cold spots your system is badly contaminated. If water is unable to circulate through a radiator due to sludge deposits the heat cannot reach that part meaning it remains cold.
If your radiators are not performing correctly, your boiler has to work harder to achieve the same results, burning more fuel and ultimately costing you money.
If your boiler has sludge build up, the heat cannot transfer into the water effectively so again the boiler has to work harder, costing more money. Also in modern boilers the waterways are small in order to achieve maximum heat transfer in the smallest amount of space, if these become blocked the boiler cannot get rid of the heat it has produced quick enough and the temperature rises quickly. If you have problems with your boiler overheating and/or noisey this could be the reason.
There are many factor that can affect the problem of sludge, Open vented systems suffer the most as the water is constantly exposed to oxygen via the feed & expansion tank and open vent pipework, Sealed systems can suffer if the initial clean was poor. also the condition of the water used to fill the system, as well as the amount of use.
With a Powerflush the sludge is mobilised, the system is cleaned, drained and flushed and the water is replaced with clean water. A chemical inhibitor is added to reduce the chemical processes and maintain a health system. It is recommended to dose the system annually to maintain continuous protection.
It is also recommended to carry out a powerflush before the installation of a new/replacement boiler. Even though your system water was drained to allow the work, sludge deposits wont have been removed without a Powerflush and will start the process all over again. It may also invalidate any manufacturers warranties if the cause of any fault was system water contamination.
How is it carried out ?
Powerflushing is a method of cleaning the inside of your heating system with a high velocity, low pressure pump and appropriate chemicals. Lynx Technical Services will carry out the flush & clean as follows:
- A thermal survey of the radiators is carried out using a thermal camera to visually highlight any heavy deposits, which will need extra attention.
- The machine is attached to the heating system and the chemicals are circulated in both forward and reverse directions, which loosens the deposits and cleans the pipework, radiators, boiler etc. (This usually takes around 10-20 minutes per radiator/boiler depending on amount of sludge. So a 7 Radiator system should take around 4-5 Hours to complete.)
- A Magnetic filter is also used to remove circulating black iron oxide contamination.
- A thermal survey of the radiators is carried out using a thermal camera to show the removal of deposits from affected areas.
- The dirty water is then pumped to a drain at the end of the cleaning process.
- The system is flushed with fresh water until it runs clear.
- The water is checked for TDS (Total Dissolved Solids) which must be within 10ppm of the property tap water.
- Once the system is clean, Inhibitor is added to stop the chemical process from re-occurring. (It is important to dose the system with Inhibitor every 12 Months to maintain continued protection.)