Water softener cost: what drives the price and the install

Ask three neighbours what their water softener cost and you'll hear three answers that seem to have nothing in common. Usually nobody was overcharged. The price of a softener is really four prices stacked together: the unit, the installation, the running costs and the upkeep, and each moves for its own reasons. You won't find dollar figures here, because they change by region and by year. The list of things you're paying for stays the same.

Before you ring anyone, write down two numbers: how hard your water is and how many people live in the house. Together they decide the size, which is where the first big cost difference begins.

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How much is a water softener? Start with the size you need

Softeners are sold by capacity in grains: how much hardness the resin holds before it has to regenerate. More capacity means more resin and a higher price. Buying too small costs you differently, because an undersized unit regenerates more often and uses more salt and water.

The sizing sum is short. It uses the same planning figures as our water softener size calculator:

1. Multiply the number of people by 75 gallons (about 280 litres) per person per day, a common planning figure for US homes.
2. Multiply that by your hardness in grains per gallon (gpg). If your water report gives milligrams per litre, divide by 17.1 to get gpg.
3. Multiply by the number of days you want between regenerations. Seven is a sensible target.
4. Divide by 0.75. Softeners are rated at their highest salt setting; run at an efficient setting they remove less per cycle, so you buy some headroom.
5. Round up to the next standard size: 24,000, 32,000, 40,000, 48,000, 64,000 grains and so on.

A worked example. Four people on 10 gpg water (about 171 mg/L) need 4 x 75 x 10 = 3,000 grains a day, or 21,000 a week. Divided by 0.75 that's 28,000, so a 32,000-grain unit fits. On 15 gpg water the same family needs 31,500 grains a week, or 42,000 after the efficiency step, so the next standard size is 48,000 grains. Same house, bigger softener, purely because the water is harder.

No recent hardness figure? A pack of water hardness test strips gives you a usable number in a couple of minutes, and your water supplier's annual report usually lists it. On a private well, get a lab test too, because iron and manganese change what you need to buy.

What drives water softener system cost

Once the size is settled, these are the things that push one quote above another.

Salt-based or salt-free

A salt-free system has no brine tank, no drain connection and often no power supply, so installation is simpler and running costs are lower. It's a different product, though. The common salt-free type changes how scale forms instead of removing hardness, so a test strip will still read hard afterwards. Compare prices only once you've decided which result you want: water that tests soft, or less scale with hard water left in place.

Metered or timed control

A timer valve regenerates on a fixed schedule whether you used much water or not. A metered valve counts gallons and regenerates only when the resin is close to full. Metered valves cost more to buy and usually less to run, since a week away doesn't trigger regenerations nobody needed. For most households that makes metered control the better buy.

Water softener installation cost: what the plumber is pricing

Most of the gap between two installation quotes comes down to what's already in place at your house.

The loop and bypass valve

Many newer homes have a softener loop: a pair of pipes near where the main enters, ready for a unit. With a loop the job is short. Without one, the plumber cuts into the main after the shutoff valve (and after the pressure tank on a well), fits a bypass valve so the softener can be isolated while the house keeps its water, and often separates the outside taps from the softened supply. Many also leave the kitchen cold tap unsoftened or add a drinking tap. Pipe size matters: if your main is 1 inch (about 25 mm), a valve built for 3/4 inch (about 20 mm) will restrict flow to the whole house.

The drain line

Regeneration sends brine and rinse water to a drain: a floor drain, a standpipe or a laundry sink. The line must end in an air gap, so waste water can never be pulled back into the supply. A drain right beside the unit costs little to connect. One across the basement, or above the softener, adds tubing, time and sometimes a pump.

The electrical outlet

Most control valves run from a small plug-in transformer and need an outlet within reach. If there isn't one, adding it is work for a licensed electrician, and the rules differ by state and town.

Permits and local rules

Some towns want a plumbing permit to connect anything to the main; others don't. A few areas, parts of California among them, restrict or ban salt-discharging softeners because the brine adds chloride to waste water. Check before you buy, not after.

Labour time

Running costs, without the price tags

A softener keeps costing a little every month. Here's what to budget for, in kind:

• Salt. The biggest ongoing item. Use depends on hardness, how much water you run through it and the salt setting. Potassium chloride works instead of sodium chloride for people limiting sodium, but it's dearer and often needs a higher setting.
• Water. Every regeneration sends a backwash and rinse to the drain. The owner's manual lists the gallons per cycle, and a metered valve keeps the number of cycles down.
• Electricity. Small: the valve's clock, display and motor.
• Resin. It lasts many years on clean water. Heavily chlorinated city water and iron shorten its life. Re-bedding a tank with fresh resin is a smaller job than replacing the whole unit.
• Filters and checks. Pre-filter cartridges, a yearly look at the valve, and a brine tank clean-out when sludge builds up.
• Salt-free systems. No salt, water or power for regeneration, but the treatment media is replaced on the manufacturer's schedule, often every few years.

On the other side of the ledger, softened water slows scale in your water heater, faucets and appliances. Our guide to hard water and limescale shows where scale does real damage, which helps you judge what a softener is worth to your house.

Installing a water softener yourself

DIY installation makes sense when most of these are true:

• A softener loop already exists, so you're connecting two fittings, not cutting the main.
• You're comfortable cutting and joining your pipe material, whether that's copper, PEX or CPVC.
• There's a drain with room for an air gap, and an outlet, within reach of the unit.
• Your town lets homeowners do their own plumbing on the main line.
• The manufacturer's warranty doesn't depend on a professional installation. Read this one carefully.

Tick all five and the saving is the labour. Tick two or three and you'll probably pay a plumber anyway, sometimes after a wet afternoon.

How to compare water softener quotes

Lay the quotes side by side and check each one against this list:

1. The sizing sum is written down. People, hardness, days between regenerations, rated capacity. If a quote just says "48K", ask for the working.
2. The water test is in writing. Hardness at minimum; on well water, iron, manganese and pH too.
3. The price is itemised. Unit, installation labour, bypass and fittings, drain line, removal of the old unit, permit.
4. The control type and settings are named. Metered or timer, the salt setting they plan to use and the regeneration time.
5. Warranty terms are split out. Tanks, valve, electronics and labour often have different periods.
6. Service is realistic. Is the control valve a common type any plumber can service, or a proprietary one only that seller supplies parts for?
7. Rental and financing are totalled. Work out the full amount over the term before you sign.

Be wary of an in-home demonstration that ends with a same-day discount, a dramatic colour-change "test" in a glass of tap water, or health claims about softened water. A good installer leaves a written quote and lets you think. Our checklist on how to choose a plumber covers licences, insurance and paperwork, which apply to softener installers as much as anyone.