Water Softeners explained

Water Softeners explained


Having lived in a very hard water area for many years and discovered the many benefits of home water softeners about 20 years ago here are my own thoughts on them.

To be clear; I am no expert and I don’t sell or supply softeners or related advice.   I am not telling you how to ‘do-it -yourself ‘ either – I very strongly advise you to get a plumber ! 

  • This blog doesn’t replace the need to read and follow all specifications, warnings, instructions, user information, regulations and manufacturers and medical instructions with great care!
  • This blog cannot and should not be considered complete, correct or appropriate to your particular situation, home or water system!
  • High pressure water is very destructive if  it gets loose!
    Please get a Qualified plumber’s advice and to do any necessary work!


  • I’m neither an expert or a plumber.  Please get an expert plumber to advise on suitability, water hardness and design and to carry out any work.  You can see if your water is hard on this map or your water supplier’s website.
    Or look in the kettle  . .


  • Most softeners remove the scale/hardness (Calcium and some Magnesium ions) from water by cleverly and permanently replacing them with different non-scaly atoms  (we are talking tiny quantities in each case).
    Water conditioners or descalers are smaller simpler devices that can temporarily reduce ‘lime scaling’ to some extent but are not generally considered to give the same ‘soft’ water, ‘foamy’ baths and showers or longer term scale protection that a softener does.


  • The softener you might need depends on your water system, the hardness of your water and the amount and maximum flow rate of water it needs to deliver.


  • If your house’s water supply mostly uses a cold water storage tank in the loft then simple low and medium capacity softeners may be fine as you also already have a reserve of stored ‘low pressure’ soft water to cover periods of high demand or the a softener’s occasional ‘recharging’ / ‘regenerating’ cycles.   In this case the small reduction in pressure / flow rate that adding the extra isolating valves and softener vessel is not usually significant as it only slightly affects the loft tank’s re-filling.


  • Water softeners can typically only soften water for a few days before they need a scheduled automatic maintenance cycle (‘recharge’ / ‘regenerate’) lasting about 60-90 minutes.
    During that time a single cylinder softener may not be able to supply any water.
    Twin cylinder softeners do one cylinder at a time so you always have some soft water.
    Note that on electronic models this cycle can often be preset to run a little early at a fixed time (say 2am) instead of as/when.   In this case any down-time may not be quite the issue some sales blurb claims.


  • If your house uses mains pressure water directly, without a loft cold water storage tank and with a combi boiler (or some large homes with Mega-flo type tanks), you will probably need a larger and more expensive high capacity / high flow type.
    • You may also wish to consider a twin cylinder type softener as these can supply some soft water ‘at all times’ if you think you need that.


  • Some Combi-boiler systems struggle to produce enough hot water for baths & showers already.  Adding a softener (of any type) will do nothing to help this so getting the water system checked and re-designed  by a competent softener-savvy plumber before installing one is absolutely essential.


  • The softener is plumbed into the incoming mains water supply pipe.  Usually this is done at a point where the garden tap and kitchen cold tap supply have already been taken off so the softener then softens the rest of the water going to either:
    • the loft cold water storage tank and then onto to the hot tank, or
    • in the case of ‘mains pressure water’ houses, the cold taps and
      combi boiler or megaflo hot tank feeding the hot taps.


  • Its recommended that the main kitchen cold tap remains un-softened to retain a direct, fresh source of water for drinking and cooking etc.
    (n.b. There are health warnings around use /drinking of softened water that you should review carefully.)  Please read your particular softener’s sales, user, installation and other literature carefully and understand their particular advice, recommendations and restrictions on this and any medical conditions.
    More here   and  here 


  • Monthly Maintenance is mostly checking /refilling the salt storage ‘tank’ with special softener salt (grains, tablets or blocks according to softener requirements).  Saltwater is automatically mixed up and used to backwash the removed hardness ions out of the softener vessel and ‘recharge it’ with new sodium ions.  The majority of the salty water and the removed hardness ions will go down the drain.


  • You will use several  (probably 3 – 10)  25kg bags of salt per year so it is worth thinking about easy access/storage of these heavy bags when locating the softener.


  • The chosen installation location needs to have access to a drain pipe, a separate overflow pipe and in many cases a 13A mains electric socket.  Smaller softeners are often neatly installed in kitchen or utility room cabinets as all the above are to hand; but if doing so, ensure that the softener power,  isolation or bypass valves are visible / accessible to you in case of a fault or breakdown.   The main picture is a BWT WS355 fited neatly into a modified kitchen cabinet


  • Internal garages and lofts are also possible locations but the softener must not be exposed to freezing conditions and for loft installations extra ‘last ditch’ overflow/flood/frost protection measures are strongly advised by manufacturers.  Some loft units are mounted inside a large water tank with another separate large overflow pipe for this reason but again get a good plumber in for this !!


  • The manufacturer’s instructions will specify in more detail how to install, test the supply, connect and set up the softener for pressures, hardness, hard/soft water blending,  timer preferences, plus bypassing for service /breakdowns and periodic maintenance.  Most makers will also recommend the softener be checked and serviced annually.
    PLEASE follow all the manufacturers instructions and recommendations !!


  • Typical softener units cost between £400 and £2000.  Installation work costs little if it is being done as part of a kitchen rip-out and replacement but if it is being retro-fitted to an existing kitchen the amount of fiddly woodwork, new pipework and messing around upside down in a kitchen cupboard can mean installation bills of £400 – 800 on top.   (All prices are wild generalisations made in 2019 🙂 )


  • Although normally totally silent in use you may notice the sounds of a recharge/regeneration cycle from time to time (Still quieter than a dishwasher even then).     Most softeners will come with a test kit so that you can confirm the softener is actually working – but usually the good lather in the bath is a good enough daily check.



I hope this post is useful.  If you have any comments, suggestions or improvements to add please do get in touch with them