Affinity Water Hardness: 200-350 ppm (2026 Data)

About Affinity Water

Affinity Water is the largest water-only company in the UK, serving 3.6 million customers across the Home Counties north of London. Chalk aquifer sources produce consistently hard water.

At 268 ppm on average, Affinity Water ranks as hard water. See how it compares across the UK in our 50 hardest water areas ranking.

All areas

Areas Served by Affinity Water

Every postcode district, sorted by hardness.

Postcode	Town	Hardness	PPM	Level
EN9	Waltham Abbey	346	346 ppm	Very Hard
EN8	Waltham Cross	345	345 ppm	Very Hard
EN7	Waltham Cross	344	344 ppm	Very Hard
EN6	Potters Bar	343	343 ppm	Very Hard
EN5	Barnet	342	342 ppm	Very Hard
EN4	Barnet	341	341 ppm	Very Hard
EN3	Enfield	340	340 ppm	Very Hard
EN2	Enfield	339	339 ppm	Very Hard
EN1	Enfield	338	338 ppm	Very Hard
WD25	Watford	255	255 ppm	Hard
AL10	Hatfield	254	254 ppm	Hard
WD24	Watford	254	254 ppm	Hard
WD23	Bushey	253	253 ppm	Hard
AL9	Hatfield	247	247 ppm	Hard
EN11	Hoddesdon	247	247 ppm	Hard
AL8	Welwyn Garden City	246	246 ppm	Hard
EN10	Broxbourne	246	246 ppm	Hard
AL7	Welwyn Garden City	245	245 ppm	Hard
AL6	Welwyn	244	244 ppm	Hard
AL5	Harpenden	243	243 ppm	Hard
AL4	St Albans	242	242 ppm	Hard
AL3	St Albans	241	241 ppm	Hard
AL2	St Albans	240	240 ppm	Hard
AL1	St Albans	239	239 ppm	Hard
WD7	Radlett	228	228 ppm	Hard
WD6	Borehamwood	227	227 ppm	Hard
WD19	Watford	226	226 ppm	Hard
WD5	Abbots Langley	226	226 ppm	Hard
WD18	Watford	225	225 ppm	Hard
WD4	Kings Langley	225	225 ppm	Hard
WD17	Watford	224	224 ppm	Hard
WD3	Rickmansworth	224	224 ppm	Hard

Recommended

Products for Affinity Water Customers

Popular choices for households on hard water.

Splendid Twin Tank Water Softener

From ~£400

Twin-tank electric softener sized for 1 to 7 bedroom homes. Removes limescale from pipes, boilers, and appliances and delivers continuous soft water, with metered regeneration to keep salt use low.

View on Amazon

Philips Shower Filter

From ~£30

A quick, affordable upgrade. Reduces chlorine and limescale at the showerhead, fits any standard UK shower hose in minutes. Protects skin and hair from hard water damage.

View on Amazon

FAQ

Common questions about Affinity Water water hardness

How do I check Affinity Water hardness by postcode?

Enter your postcode in the checker on the WaterHard.uk homepage, or find your district in the table above. Affinity Water serves 32 postcode districts across Home Counties, ranging from 224 to 346 ppm.

Is there a Affinity Water hardness checker or map?

Affinity Water publishes water quality data by postcode, but it can be scattered across PDF reports. WaterHard.uk compiles it into the searchable table above so you can find your district's reading in one place.

How hard is Affinity Water water in my area?

It depends on your exact postcode. Affinity Water supplies range from 224 ppm to 346 ppm, averaging 268 ppm (hard) across 32 postcode districts in Home Counties. Use the table above to find your specific district.

Do I need a water softener with Affinity Water?

At 268 ppm (hard), many households on Affinity Water notice limescale in kettles and showerheads within weeks. A shower filter is the cheapest first step; a whole-house softener gives the most complete protection. See our water softener guide for a full comparison.

Get free water softener quotes

Tell us about your home and we will match you with quotes for softening your hard water. No obligation, takes under a minute.

Affinity Water Hardness