Water treatment of central heating systems is considered by many to be a wise and prudent investment in the long term future of their heating system. Many others, who thought otherwise, have often had an instant change of heart when a radiator starts leaking through ‘pin_holing’ or their boiler develops a banging noise when it fires up.
Before any new central heating installations are chemically treated the recommendations of dealers should be taken into account. However, most dealers will endorse chemically treating a system because it can provide long-term protection to the boiler as well as the rest of the system.
There are many reason for treating a system but the main problems are Corrosion, Lime Scale and Microbiological Growth. The use of a ‘Water Analysis Kit’ will quickly indicate the condition of a system.
Corrosion occurs the moment water enters a system. It happens faster when the water is hot. Corrosion is generally the result of oxygen being present, but it can also be brought about by ‘galvanic’ action, which occurs when different metals are connected. Aluminium is especially prone and should never be connected directly to copper or brass.
One of the most apparent result of corrosion is the formation of a black, magnetite sludge, which forms in radiators, boiler heat exchangers, pumps and pipework. Such deposits in radiators can restrict circulation and cause ‘gassing (hydrogen formation) so the radiators need to be ‘bled’ often. Magnetite deposits also cause premature pump and in boilers can cause bumping and banging noises.
Corrosion, formed as a result of an overuse of flux (used for soldering fittings) and poor initial flushing, can sometimes produce ‘pin-holes’ in radiators.
For further help or guidance on which treatment to use for a particular problem, please contact your dealer.
Lime Scale formation varies considerably depending on the area you live hence, water hardness.In hard water areas, the high lime content can cause rapid ‘furring’ of boiler heat exchangers.
Where a long term system leak is present and has gone undetected, the constant introduction of fresh water, through the feed and expansion tank, will cause a perpetual deposit of lime scale at the point of highest temperature, the boiler heat exchanger. It has been known for scale at the point of highest temperature, the boiler heat exchanger. It has been known for such deposits to cause cast iron heat exchangers to crack, but well before that occurs, other consequences will be an increase in fuel use and often an annoying ‘Kettling’ noise to be heard, sometimes throughout the whole house.
For futher help or guidance on which treatment to use for a particular problem, please contact your dealer.
Microbiological Growth occurs in feed and expansion systerns open to the air in lofts and elsewhere. Such open tanks are prone to contamination from all sorts of micro organisms, such as bacteria and fungi and once in the system they can breed and give rise to unpleasant growths and slimes, which can foul the heating system and cause blokages and deposits.
For futher help or guidance on whicn treatment to use for a particular problem, please contact your dealer.
“Hard water” is water containing a quantity of dissolved minerals. When hard water is heated, the carbonates precipitate out of solution, forming scale on the heat surfaces.
Soap is less effective in hard water because its reacts to form the calcium or magnesium salt of the organic acid of the soap.
“Soft water” is treated water where the only cation, the positively charged ion, is sodium.
|Dissolved Calcium and Magnesium|
|Water||Milligrams per Liter
|Grains per Gallon
|Soft||0 – 60||0 – 3.5|
|Moderate||61 – 120||3.5 – 7|
|Hard||121 – 180||7 – 10.5|
|Very Hard||> 180||> 10.5|
Hard water can be softened by passing it over an ion exchange resin.