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With London’s ‘soft water’ Do You Really Need A Power Flush?


There is an easy but lazy answer – e.g. IF you want to ignore the problems of living with London’s pretty crappy water quality you can rely on what the water board tells you. Do not worry about it. Move along, nothing to see here.

It’s not real though is it?! Londoners know how bad the water is. Chlorine is not something that should be added to water – it’s a toxin, pure and simple. A powerful bactericide added to kill the bacteria that are not removed by Thames Water’s “purification system”. Ever wondered why chlorine needs to be added at all if what comes out of the tap is already good and pure enough to drink? Did you know that the water you drink has already been through the human body about seven times?

The real answer though is a resounding YES!! It’s not the limescale in the water that causes problems inside radiators (most of the time) it’s the oxygen in the water. When water is added to your central heating system it should also get a good does of corrosion inhibitor. Some school chemistry here. H2O = water. Fe = iron. Oxygen is hightly reactive and if it can find somehwere to attach itself it will jump over right away and attach on to any spare piece of Fe that it can. FeO3 = Iron Oxide (rust) and then the Hydrogen molecule it was attached to floats around the system always looking for the hightest point and either goes out through your vent pipe never to be seen again. OR, it collects in the top of your radiator until you notice that the top of the radiator is cold and let the gas out. Most people think they are letting air out, but in reality it’s probably hydrogen.

One easy way to test for yourself is to hold up a lighter or a match when you let the gas out and see if you get a little blue flame or a popping sound. Make sure you move the curtains out of the way!!

So, as you have read, it’s not the limescale in the water that causes most problems in central heating systems. It’s the water that has not been ‘neutralised’ with corrosion inhibitor.
So dose you up your central heating water with something like Kamco’s SystemSafe or Sentinel X100. Personally, I prefer not to use Fernox.

If you don’t take care of this, eventually you will have such a build-up of rust in the system that you will be forced to either replace pipework and radiators or to get a powerflush. And by the way, if you do ever find yourself in need of a
london power flush company you could do worse than to take a look at Bob Jones’ website at He’s one of the good guys. Other power flushing companies are available but Bob was one of the first in the country and has worked on over 3000 systems now.