What is a Powerflush?
When your central heating system has been running a good few years it is almost unavoidable that sludge and other forms of debris will build up in the system, reducing its overall efficiency. The system will be slow to warm up and be wasting energy as well as corroding from the inside. You will notice the radiators have cold spots, the boiler or pump may be getting rather noisy and sometimes the hot water may be cloudy in appearance.
These are all tell- tale signs of sludge, lime scale and rust build- up in the system that needs to be removed. The solution to this is a procedure known as a powerflush which utilizes a high- pressure chemical cleaning solution that is pumped through the entire system that dissolves the sludge, chemically treats any corrosion in the pipes, breaking up the rust and lime scale particles at the same time. An easy way to tell if the system contains sludge is to take a sample of the water after the system has been circulating for about 30 minutes, about 500mls and look at it through bright light in a clear glass container- if it is dark and cloudy, you have sludge in the system that needs removing.
A powerflush is a far more effective solution than simply flushing the system with water, as this would not remove sediment like lime scale, rust or sand plus it would not make any difference to the corrosion. The chemicals used in a powerflush include an acid which will help to neutralize and break up the larger flakes of rust that are often present. The best time to do this is when you are having your boiler serviced or particularly if it is going to be replaced, otherwise the sludge that is already in the pipes is going to cause damage to your new unit as soon as it is connected.
On average a powerflush will take 6-8 hours, depending on the size of the central heating system and how severely clogged it is. It can be an expensive job (averaging around £600-£800) but it can often be a smart investment in the long term as it can save you the cost of even more expensive repairs in the future as well as helping to reduce your energy bills. If you shop around you can get a good deal, just make sure it is carried out by an accredited professional.
If your system is quite new then a powerflush is unlikely to be appropriate and you may simply need to have the system drained and re- filled plus the right anti- rust chemicals added to the water in the heating system, which would be considerably cheaper. A great option to consider is to have a Magna Clean unit installed straight after a powerflush. This is a unit that filters and collects (using a magnet) all the iron oxide particles in the system, effectively protecting your central heating from sludge build- up in the future and keeping the water clean and circulating freely.