Which phosphate scale reducer ?

Hi,

Sorry if this seems a bit of a stupid question. After spending quite alot of money on my combi boiler getting the heat exchanger replaced due to scale build up, i've been advised to add a phosphate limescale device on the cold inlet.

However there seems to be around 4 different types and the price seems to vary quite alot. Can anyone advise if there is any difference between:

• 
  CombiCare approx £100 http://www.loheat.co.uk/loheat_scale_reducers.htm
  
  Cal-Mag approx £65 http://www.discount-heating.co.uk/s...uct_info&cPath=1018_197_203&products_id=24657
  
  CombiCare approx £50 http://www.waterdial.co.uk/p_aquadial/combi-care.php
  
  No-name from B&Q for approx £40

Or do they all do the same thing and I should just go for the cheapest ? It seems the replacement cartridges / spheres all seem to be roughly the same cost ....

Cheers

Andy

They all do the same thing, but use the £100 one. The combi-mate is a much better engineered thing, the cartridge jobs are not very good, IMO.