Softening Water – Installing A Water Softener

Most people in developed countries such as the UK and America take the quality of their water for granted; but the water which comes out of the taps is often far from perfect. Depending on the location it is soft, moderately soft, slightly hard. Moderately hard, hard or very hard — and it is these classifications which affect the home to a much greater extent than is often realized.

Types of water

Pure water does not exist in nature. The nearest approach to purity is rainwater, although even this picks up gases, dirt, soot and other impurities as it falls through the air. When it reaches the ground it collects even more impurities, depending on the type of soil and rock with which it comes in contact. Surface water Scotland, parts of Northern England. Wales and the West Country have a high rainfall and a rocky terrain giving rise to surface water, which tends to pick up organic matter in the form of such things as decaying vegetation and animal matter. This water is relatively soft.

Ground water

The rest of Britain, including parts of the North, East Anglia, most of the Midlands, the South and South East, has a sedimentary geological structure; so water drains down to a water table. This ground water dissolves calcium and magnesium, iron, silica and other mineral salts from the porous chalk and limestone through which it flows. This water, with its high dissolved mineral content, is relatively hard.

Hard and soft water

As already mentioned earlier in the Course, the classifications of water are part of a system of measurement from which you can tell to a greater or lesser extent the degree of calcium and magnesium carbonate hardness in water. This is expressed in parts per million of carbonate hardness or degrees of hardness, as indicated in the following table.

Classification – Degree – PPM

  • soft 0-3 0-50
  • moderately soft 3-7 50-100
  • slightly hard 7-11 100-150
  • moderately hard 11-14 150-200
  • hard 14-21 200-300
  • very hard over 21 over 300

The effects of hard water can be quite dramatic and it is in the kitchen and bathroom that hard water can be seen to be most damaging — furring up kettles, scumming and discolouring baths and wash-basins, blocking shower roses, leaving stainless steel surfaces greasy and spotty, clogging washing machines and hindering the operation of dishwashers.

But plumbing is probably the greatest sufferer, since scale deposits accumulate on immersion heaters and other heat transfer surfaces; more fuel is therefore needed to heat the same quantity of water. Tests have shown 15 percent more fuel is used when scale is 1.5mm thick, 20 percent with 3mm scale, 39 percent with 6min scale and 70 percent with 13mm scale. This is not only a waste of energy while the scale is forming. But also expensive when it comes to replacement. Especially when a breakdown due to scale deposits can occur within four years in an area of 28 degrees (400ppm) hardness.

It is generally accepted hard water problems become most apparent in areas of over 16 degrees (229ppm) hardness. Most of the heavily populated areas of Southern England are affected; London, for example, has 20 degrees (286ppm) hardness. If you want to check on the hardness in your area, the local water authority will be able to give you the information.

Living in a soft water area is, therefore, of considerable advantage. There is none of the scaling of hot water pipes or tanks which can lead to water pressure problems or inefficient heating systems and soft water will mean lower housekeeping bills, especially those related to soap powder.


Naturally soft water can be slightly acidic in some areas and this aggressive characteristic can set up a corrosive action in plumbing systems. The problem can be overcome by adding a proprietary non-toxic corrosion inhibitor to the water system, as described earlier in the Course. In any event, the advantages of living in a soft water area far outweigh any of the minor disadvantages. It should be noted hard water is rarely aggressive and water softening does not cause acidity to develop.


This can be cured in the same way as corrosion; scale inhibitors can be introduced into the water system, as described earlier in the Course

But they will not, of course, soften water. The installation of a water softening appliance will not only prevent all the problems of hard water already outlined, but will also slowly remove existing scale deposits.

Water softeners

The water softener has existed in various forms since the early 1900s, but it was not until quite recently that automatic machines became available. Modern automatic domestic softeners are designed to blend into most kitchen or bathroom settings and are manufactured in a range of sizes to meet the varying requirements of the house and family.

  • If installing a softener outside Britain, it will be necessary to check with the relevant local authority since different factors affect water in different parts of the world and the mineral content will vary.
  • As with most appliances, the bigger the unit the greater the capacity it has for producing softened water. The choice will, therefore, depend on the size of the home and family in relation to the hardness of the water; it is important you ask the manufacturer or your local supplier for advice on exactly the right model to suit your needs, bearing in mind the area in which you live.
  • It has been estimated the benefits and savings on household purchases related to a water softener can cover the initial cost of the appliance within five or six years

Installing a water softener

Since a water softener is plumbed into the rising main, the positioning of the appliance could be in one of any number of areas in the home. But bear in mind there must be access to an electrical power circuit and a suitable drain outlet. The plumbing in of the average appliance is no more complicated than for a washing machine and is a job which can be tackled by the competent DIY worker, provided the manufacturer’s instructions are followed.

Before deciding on the siting of an appliance. Remember if you prefer to drink hard water you must leave the kitchen cold tap supplied from the rising main below the water softener — or install a separate tap in this position. If you do keep the kitchen cold tap on hard water supply, you will not prevent the problem of fur in the kettle. Outside taps should remain on the hard water supply.

Plumbing in a softener

Once the water softener has been sited near the rising main and a suitable drain outlet, you will have to alter the existing pipework above the main stopcock. To make any servicing or moving of the appliance easier, you should fit a bypass. Two compression tees and a bypass valve are fitted into the rising main and an inlet and outlet valve suitably positioned in the new pipework so you can isolate the softener from the water supply.

Depending on local regulations, you may also have to fit a non-return/air brake valve assembly between the inlet valve and the appliance. In some areas subject to high water pressure it may be advisable to fit a pressure reducing valve between the main stopcock and the inlet valve to the water softener. This will not only safeguard the appliance, but will also prevent water pressure problems in dishwashers and washing machines.

Waste outlets

A water softener has a waste outlet which can be run into any open gully or stack pipe. A standard 32mm plastic pipe system is adequate and the fitting arrangement is similar to that required for a washing machine. The hose normally supplied with the appliance for this purpose is cut to length and clipped onto the drain spigot before being inserted into the waste pipe. A second length of hose connected to the overflow spigot must be passed through an outside wall as a warning pipe. Final connection After checking the new pipework is free from swarf and debris, make the final plumbing connections to the softener and fill it with granular salt to the recommended level.

Wiring up a softener

Most water softeners operate from a 220/240v supply and can be connected through a normal socket outlet. Most manufacturers, however, recommend the appliance is wired to a fused connection unit to prevent you accidentally switching it off. The supply should be fused at 3amps.

The electrical supply is needed to operate the softener’s time clock, on which the regeneration sequence is programmed. This sequence will vary depending on the size of the house and family and the hardness of the water. The programming of the softener is a fairly simple operation described in the manufacturer’s instructions.

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