The new Energy Efficiency Standard Regulations recommend that ALL systems are Chemically Treated or Power flushed. They also recommend that ALL systems now have a minimum of the following:
1. Thermostatic Radiator Valves
2. A Room Thermostat
3. A cylinder Thermostat
4. Motorised Zoning valves
5. Inhibitor chemicals
Boiler Manufacturers now insist that the system is flushed prior to fitting or it will invalidate the warranty. It is also good practice to have a Magnetite Filter fitted on all types of systems and A Water Conditioner Unit as well on Combination systems.
When a new central heating system is installed the whole system should be flushed as part of the commissioning process. This removes any debris or chemical deposits from the system. After flushing corrosion inhibitor is added to the system to protect the system.
Why systems corrode
If a system is designed and installed correctly and was flushed out correctly and inhibited, the water in the system will stay clean providing you do not have a water leak. However If your system has been drained and corrosion inhibitor was not added when refilling your system; your system is open to corrosion problems accelerated by the introduction of fresh oxygenated water.
Open vented fully pumped systems are more susceptible to corrosion problems than sealed systems. We have flushed sealed systems of sludge which looked like used engine oil. Typically on a sealed system the original inhibitor will have been lost due to either a slow leak, age, or through the pressure relief valve, causing frequent topping up of the system resulting in complete loss of the inhibitor and the introduction of dissolved air. Fresh introduction of water into a system is the biggest cause of oxygenation which is the main contributor to sludge.
We have also been called to flush sealed systems where the radiators were rotting because acidic cleaner had been left in the system on installation.
The Corrosion Process
- The oxygen content of air dissolved in the system water will react with the iron content in steel radiators to produce rust and hydrogen as by-products. Often when venting a radiator you will be releasing hydrogen and not air.
- The rust, hydrogen and heat can produce further chemical reactions within the system. The end product, commonly seen, is magnetite or black sludge.
- Electrolytic action may cause dezincification of brass leading to carbonate deposits in the system.
- If your system was not flushed thoroughly on installation there may be further chemical components which enter the reaction.
- Black or Dirty water
- Cold spots on radiators.
- Blocked radiators.
- Radiators frequently needing venting & bleeding.
- Boiler noise.
- Boiler failure or lockout.
- Noisy pump.
- Pump failure.
- Heating circulation problems
- System is slow to heat up
- Reduced heating output.
- Pinhole leaks from radiators.
- Blocked inoperative or leaking radiator valves.
- Sludge and rust deposits form (these are actually chemically changed parts of what was once your central heating system and turn the water a Very Dirty colour).
- In hard water areas lime scale may also form on the boiler heat exchanger leading to “kettling” and boiler overheat problems.
- The narrow water channels of plate heat exchangers become blocked leading to hot water problems on combination boilers
- Radiators will corrode from the inside leading to leaks and requiring replacement of radiator.
- Aggressive water content may attack rubber diaphragms and seals within the boiler.
- Your boiler may contain sophisticated sensors, switches and capillaries which will block leading to boiler failure and expensive boiler repairs or replacement.
- The abrasive nature of the sludge may lead to premature pump failure and motorised valve failure.
- EXPENSIVE REPAIR BILLS........
Corrosion Inhibitors & Filters
As the name suggests, a Corrosion Inhibitor decreases the corrosion rate within a system. Systems should be treated every 2 yrs max..
A typical central heating system will include a various metallic components, copper, brass, iron, steel, aluminium which when combined with contaminated water can lead to electrolytic action. This process is more aggressive when the system is heated.The best corrosion inhibitors react with the metallic inner surfaces of the system to produce a protective film coating.
Magnetite filters are generally fitted on the return pipe to the boiler to prevent debris entering the heat exchanger. They remove tiny metallic particles from the system by means of water flowing over very strong magnets. These units must be checked and cleaned Annually.
There are many types of Mains Water Conditioners used and we have found that the best water hardness results come from Siliphos Ball or Cartridge type. Mains water conditioners are fitted to the main water inlet of Combination Boilers. If they are the Siliphos Ball or Cartridge, the balls and cartridges must be changed yearly for maximum protection.
Inline magnetic units should be changed according to the manufacturer’s instructions.
In-line Filters and Electrical Wrappa have not always produced the results that we would expect to find in order to prevent scale build up.
The Power Flushing process
We use a low pressure, high velocity, high volume, dedicated flushing pump. We use specialist chemicals to loosen and mobilise any deposits and remove any stubborn coatings to the inside of your system then flush them out. The chemicals used to cleanse or descale your system will be chosen to suit your individual system requirements. The flushing pump has an instantaneous flow reversal feature to aid the process. Your system will be cleansed internally, methodically and thoroughly, pipe by pipe, radiator by radiator, including the boiler. Once your whole system has been cleansed thoroughly we refill with clean water. On completion we will add corrosion inhibitor to your system. We will label your system, confirming that your system contains corrosion inhibitor.
How long does it take?
This depends on the type of system you have and the number of radiators but we can usually complete the process in one day.
Will Power Flushing damage my system?
Power Flushing will not actively damage your system. Nor will it repair internal corrosion damage to your system. On rare occasions the removal of deposits may expose small leaks which had been blocked by the deposits.
We believe it is preferable to identify any potential leaks before they occur spontaneously.
Would you prefer that a leak waiting to happen sprang on Christmas Day?