HOW TO HIRE · PLUMBING & HEATING

How to hire a water softener installer in the UK
The checks, the questions and the paperwork.

No register applies, but a softener on your main must meet the water fittings rules, including backflow protection. The checks and the quote.

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THE 60-SECOND VERSION

Hiring a water softener installer in five steps

  1. Test your waterAsk your water supplier how hard it is, or have it tested before choosing.
  2. Size for the householdA bigger family needs a higher-capacity softener.
  3. Find the spaceNear the stopcock, with a drain for the regeneration water.
  4. Decide on a hard-water tapWhether you want an unsoftened tap kept for drinking.
  5. Check the valvesBypass and isolation valves, and backflow protection, in the price.

BEFORE YOU BOOK

Check before you book

No register applies

No licence or register applies to water softener installers in England, Wales, Scotland or Northern Ireland, so anyone may offer a water softener installation. For a water softener installation, two legal lines remain: gas work belongs to a Gas Safe registered engineer, and new fittings must meet your nation's water fittings rules.

Ask whether any part of the water softener installation touches gas, and if it does, who on the team is on the Gas Safe Register.

Backflow under the water fittings rules

Schedule 2 of the 1999 Water Supply (Water Fittings) Regulations requires a suitable arrangement to stop backflow wherever a fitting could contaminate the supply. A softener connected to the main is that kind of fitting; Scotland and Northern Ireland have equivalent rules.

Ask which backflow device the water softener installation will include. legislation.gov.uk →

Water fittings rules

In England and Wales the 1999 Water Supply (Water Fittings) Regulations govern the pipes and fittings used for the water softener installation; an approved contractor must give the person who commissioned the work a certificate saying whether the fittings comply. For the water softener installation in Scotland the rules are Scottish Water's byelaws, and in Northern Ireland the 2009 Regulations.

Ask whether the plumber is an approved contractor and will give you the certificate for the the water softener installation. legislation.gov.uk →

Public liability insurance, including water damage

No law requires a plumber to be insured for the water softener installation, but one leaking joint can ruin a ceiling. The Consumer Rights Act 2015 gives you the right to the water softener installation done with reasonable care and skill — insurance is what makes a claim against the installer worth something.

Ask the installer for the insurer's name and whether the policy covers water damage.

VAT

Fitting a water softener is standard-rated at 20%, the bypass and drinking water tap included. Once a business's taxable turnover goes over £90,000 it must be registered, and the VAT then goes on the quote as its own line.

Ask the water softener installer for the VAT number and whether the price is plus VAT. gov.uk →

“What capacity of water softener do we need?”

A good answer: A size worked out from the water hardness and the number of people, not the biggest unit.

“Where will the water softener go, and where does its waste run?”

A good answer: A position by the incoming main, with a drain or overflow connection.

“Will there be a bypass valve?”

A good answer: Yes, so the water can run while the softener is serviced.

“How is backflow prevented?”

A good answer: A named check valve or device, as the water fittings rules require.

“Can we keep an unsoftened drinking tap?”

A good answer: Yes, priced as its own line.

“What servicing does the softener need?”

A good answer: Salt top-ups and a service interval, with the cost.

Getting the quote right

  • Softener model and capacity
  • Bypass, isolation and backflow valves
  • Drain and overflow connection
  • Drinking water tap, if wanted
  • Who actually attends to plumb in the softener — employed staff or a subcontracted plumber
  • The VAT number, and VAT at 20% listed separately

Walk away if

  • No hardness test or question about it
  • No bypass or backflow valve
  • Waste piped nowhere sensible
  • A service contract pushed into the sale
LOW
£500
TYPICAL
£800
HIGH
£1,500

What a water softener installer costs: £500–£1,500 per install

Water softeners are priced as an installed unit; the softener, the pipework to the main and a drinking tap set the figure. Water Softener Installation price guide →

Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.

KNOW WHAT TO LOOK FOR? NOW FIND ONE

Water softener installers near you, with the badges that matter shown

ID checked, trader status and one score from every review — on the card, before you message anyone. Nearest first. No account needed to look.

Or post the job free and let them come to you.

  1. TestWater hardness tested to set the softener up.
  2. IsolateWater off at the stopcock.
  3. Plumb inSoftener connected to the main with bypass, isolation and backflow valves.
  4. DrainWaste and overflow connected for regeneration water.
  5. CommissionProgrammed, salted and the softened water tested.

Hard water
Water high in calcium and magnesium that leaves limescale.
Regeneration
The softener cleaning itself with salt water, sent to the drain.
Bypass valve
Lets water skip the softener during servicing.
Backflow
Water flowing back into the supply pipe.
Check valve
A one-way valve that stops backflow.
Rising main
The incoming cold water supply pipe.

AFTER

When the job is done

Test the waterHardness checked at a tap after the softener is set up.
Keep the manualSettings, salt type and service interval.
Check for leaksRound the valves and the drain connection over the next days.
Say how it wentYour rating of the water softener installation sits on the water softener installer's Locufy profile for others to read. Something wrong? Use make-it-right first and we follow it through.

STEP 1Put it in writing to the water softener installerGive the water softener installer a clear written account and a fair deadline. The law treats the water softener installation as a service that had to be done with reasonable care and skill, and where it was not, the trader must redo it at their expense or refund part of what you paid.
STEP 2Use the make-it-right stepRate the water softener installation below four stars and you are asked whether the water softener installer should see the complaint first; we keep it moving until it is answered, then you review.
STEP 3Trading Standards, through the helplinesTrading Standards is reached through a helpline, not directly: Citizens Advice on 0808 223 1133 in England and Wales, Advice Direct Scotland on 0808 800 9060, and Consumerline on 0300 123 6262 in Northern Ireland can log a complaint about the water softener installer and pass it on.
STEP 4Small claims, if money is owedTo get money back for the water softener installation, the small claims limits are £10,000 in England and Wales, £5,000 in Scotland (simple procedure) and £5,000 in Northern Ireland; court fees start at £35 in England and Wales and £23 in Scotland.

Hiring a water softener installer: questions people ask

No register applies. The softener must meet the water fittings rules, including backflow protection.

An approved contractor can certify that the new fittings comply; otherwise an invoice.

Yes. The 1999 water fittings rules in England and Wales require a suitable arrangement to prevent backflow.

£500–£1,500 per install, about £800 typical for a mid-range unit. There is more in the water softener installation price guide; enter a town above to see installers who work there.

Your water supplier can tell you; a test strip gives a quick reading.

Two to four hours for most installations.

MORE GUIDES

More hiring guides in plumbing & heating

How to hire: Kitchen PlumbingHow to hire: Tap & Mixer InstallationHow to hire: PlumberHow to hire: Pipework InstallationHow to hire: Water Tank InstallationHow to hire: Bathroom PlumbingHow to hire: Shower InstallationHow to hire: Leak RepairAll 701 hiring guides →

Water softener installers near you

Water softener installers in LondonWater softener installers in ManchesterWater softener installers in BirminghamWater softener installers in GlasgowWater softener installers in BelfastAll water softener installers on Locufy →

Sources — checked October 2026

  1. Water Supply (Water Fittings) Regulations 1999, regulation 5 — notice to the water undertaker
  2. Water Supply (Water Fittings) Regulations 1999, regulation 6 — contractor's certificate
  3. Water Supply (Water Fittings) (Scotland) Byelaws Extension Order 2024
  4. Water Supply (Water Fittings) Regulations (Northern Ireland) 2009
  5. Gas Safety (Installation and Use) Regulations 1998, regulation 3
  6. Water Supply (Water Fittings) Regulations 1999, Schedule 2 — requirements for water fittings
  7. Consumer Rights Act 2015, section 49 — reasonable care and skill
  8. Citizens Advice — more help with a consumer issue (England)
  9. Buildings and construction (VAT Notice 708) — 2.1 Construction services: work to an existing building is normally standard-rated
  10. GOV.UK — VAT rates
  11. GOV.UK — Register for VAT: when to register