I am thinking of buying one of these, a major brand name. In my area the water is very hard and I am forever descaling the kitchen drainer and around the taps.
The adverts claim that not only will it prevent further limescale but also over time descale the existing build-up.
Does anyone have any experience of these ? Do they come and fit them for you ?
If it's what I've got they are useless. We bought one a few years back and hasn't really helped much. Water is still v.hard and have to descale kettle and shower head regularly.
I did buy a Permutit "descaler", which was a wire that wrapped around the cold water inlet pipe. I didn't think it made any difference, so after a year we bought a water softener, which did make a big difference!
The theory is that it prevents scale build up in the pipe to which it is attached. Of course that means that all the solids which might have been deposited in the pipes will now be deposited in your kettle instead!
As Rojash says, conditioners change the 'shape' of the scale molecules so they don't stick to surfaces so readily - that's the theory, anyway. They don't soften the water and you will still get limescale in the kettle. Personally I never found them very effective and have resorted to a water softener.