An ion-exchange softener replaces the calcium and magnesium that cause hardness with sodium, so no scale can form anywhere downstream. It needs a drain, a power supply, space, and – under the water fittings regulations – a hard water tap retained for drinking and food preparation.
Why this matters more here than almost anywhere
Norfolk sits on chalk. Rain falls, percolates through it, and dissolves calcium carbonate on the way down. By the time it reaches the aquifer and then your tap, it is carrying a substantial dissolved mineral load – and every time you heat it, some of that comes back out of solution as scale.
The Drinking Water Inspectorate, the statutory regulator, classifies water in bands by calcium carbonate content: soft up to 100 mg/l, slightly hard 100 to 150, moderately hard 150 to 200, hard 200 to 300, and very hard above 300. Most of this region sits in the upper bands.
Plenty of websites will tell you a hardness number for Norwich. Those figures are third-party aggregations we have not been able to verify against the water company, and we are not prepared to publish a number we cannot stand behind. Anglian Water’s own water quality portal will give you the figure for your supply zone, and that is the one to use. Our water hardness checker explains the bands and the unit conversions.
What scale actually does
The damage is not the crust round the taps. It is what happens on heat transfer surfaces.
| Where | What happens |
|---|---|
| Boiler heat exchanger | Scale insulates the exchanger, so the boiler burns more fuel to deliver the same heat. On a combi’s plate heat exchanger it also restricts flow, which is why hot water pressure drops over the years |
| Hot water cylinder coil | The coil transfers heat from the boiler to your stored water. Scaled, it transfers less, so the cylinder heats slowly and never quite gets there |
| Immersion heater element | Scale forms on the hottest surface, insulates it, and the element overheats inside its own deposit until it burns out |
| Shower heads and aerators | Blocked orifices, poor and uneven flow. The most visible symptom and the least important one |
| Tap cartridges | Abrasive scale particles score the ceramic discs, so taps drip and stiffen far sooner than they should |
| Washing machines and dishwashers | Elements and heat exchangers scale up the same way, and detergent efficiency drops sharply in hard water |
| Pipework | Bore reduction over decades, which is a slow and largely invisible cause of falling flow |
The pattern to notice is that every one of those is a heat transfer surface or a small orifice. Scale does not damage the plumbing generally; it damages the specific things you paid most for.
How a softener works
An ion exchange softener contains a resin bed of small beads carrying sodium ions. Hard water passes through, the calcium and magnesium swap places with the sodium, and what leaves is water with no scale-forming minerals in it. Chemically it is a genuine removal, not a treatment – the hardness is gone, not conditioned.
Eventually the resin runs out of sodium to trade. The unit then regenerates: it draws a strong brine solution from a salt reservoir through the resin, which flushes the accumulated calcium and magnesium to drain and reloads the beads with sodium. A modern metered unit does this based on how much water you have actually used rather than on a timer, which uses considerably less salt and water.
There is a fuller explanation in how an ion-exchange water softener works.
What an installation needs
- Space, usually under the kitchen sink or in a garage or utility. Block salt units are more compact; tablet salt units need a taller cabinet. Access for loading salt matters more than people expect – a unit in an awkward corner becomes one that never gets topped up.
- A drain connection for the regeneration discharge, with a proper air gap so there is no possibility of backflow.
- A power supply for metered units, usually a standard socket.
- Installation on the rising main after the incoming stopcock, so the whole house is treated.
- A retained hard water tap. This is a regulatory requirement, not a preference – see below.
- A bypass valve, so the softener can be isolated for servicing without shutting the house off.
The Water Supply (Water Fittings) Regulations require that a supply of unsoftened water is retained for drinking and food preparation. In practice that means the kitchen cold tap is taken off before the softener. Softened water carries a small amount of added sodium, and it is also not suitable for filling a fish tank or watering certain plants. An installation that softens everything including the drinking tap is not compliant.
Is it worth it for your house?
An honest assessment rather than a sales pitch, because a softener is not automatically right for everyone.
Strong case
A house with an unvented or vented cylinder, a combi with a plate heat exchanger, several bathrooms, and a family using a lot of hot water. The protection of the cylinder coil and the boiler is where the money actually is, and those are the most expensive things in the system. If you are replacing immersion elements every few years, that is the water telling you plainly.
Weaker case
A small flat with a modest hot water demand and no cylinder, where the annoyance is mainly kettle scale and shower heads. A scale inhibitor may well be proportionate – see scale inhibitors and softener or scale inhibitor.
Things people like that nobody mentions in advance
Soap and detergent go much further, showers feel different, glassware stops clouding, and the constant low-level cleaning of scale off everything stops. Some people find softened water feels slippery and take a while to get used to it – that is the soap not being stripped by calcium, and it is normal.
Not sure whether you need a softener or an inhibitor? The answer depends mostly on whether you have a cylinder. Call and we will tell you straight.
Servicing and running it
A softener needs salt and very little else. Good practice is: keep the salt topped up rather than letting it run empty, have the settings checked against your actual hardness and household size, and check the brine tank occasionally for a salt bridge – a crust that forms across the top and leaves an air gap, so the unit appears full while the resin gets no brine at all. A softener with a salt bridge stops softening silently.
We install, service and repair softeners, including units we did not fit. Where an existing installation is not compliant – most commonly because the drinking tap is being softened, or there is no air gap on the drain – we will tell you and put it right.
Questions we get asked about this
Is softened water safe to drink?
The regulations require a hard water tap for drinking and cooking, and that is what we fit. Softened water contains a small amount of added sodium in proportion to the original hardness, which is why the drinking supply is kept separate – particularly relevant for anyone on a sodium-restricted diet or making up infant formula.
How much salt will it use?
It depends on your hardness, how much water you use, and whether the unit is metered or on a timer. A metered unit regenerates only when the resin is actually exhausted, which is substantially more efficient. We set it from your real figures rather than leaving it on factory defaults.
Block salt or tablet salt?
Block is cleaner and easier to handle, tablet is generally cheaper per kilo and used by a wider range of machines. Which suits you depends more on the unit and on who is lifting the salt than on performance. See block vs tablet salt.
Will it remove existing limescale?
Not immediately, but softened water is aggressive towards existing scale and will gradually dissolve deposits in the pipework and appliances over months. It is a slow reversal rather than an instant one.
Does it need a drain nearby?
Yes – regeneration discharges brine and it has to go somewhere, with a proper air gap. That requirement is often what determines where the unit can go, which is why the siting is a survey question rather than an assumption.
Can I fit one myself?
Physically it is not difficult. The parts people get wrong are the hard tap requirement, the drain air gap and the bypass arrangement – all of which are regulatory rather than optional. An installation missing those is not compliant.
Will it protect my boiler warranty?
It protects the boiler, which is the substantive point. Some manufacturers make specific reference to water treatment in hard water areas. It is worth checking the installation manual for your appliance, and worth doing regardless of what it says.
Sources
- Drinking Water Inspectorate, water hardness classification — https://www.dwi.gov.uk/consumers/learn-more-about-your-water/water-hardness-hard-water/
Regulations and standards referenced on this page
- The Water Supply (Water Fittings) Regulations 1999 (SI 1999/1148) — UK Statute Law Database
What happens when you call
Call and describe it
You speak to an engineer, not a call centre. Most jobs can be narrowed down on the phone.
We look at it properly
A real diagnosis before a price, and a straight answer if it is not worth doing.
A written quote
Itemised, so you can see what you are paying for.
The job, and the paperwork
Certificates where the work needs them, and what will need attention next.
Where we do this work
Across Norwich and the whole of Norfolk. If you are on the edge of the county, call and ask — we will tell you honestly whether we are the right people.
- Norwich
- Wymondham
- Dereham
- Attleborough
- Aylsham
- North Walsham
- Cromer
- Diss
- Loddon
- Long Stratton
- Watton
- King's Lynn
Need this doing?
Call and describe the problem — you will speak to an engineer, not a call centre. Written quotes, no estimates over the phone.