Water hardness

NN11 Daventry

Harder than the UK average. Expect visible limescale on kettles and taps.

At 256 ppm, Daventry sits among the UK's hardest water areas — compare it against the softest areas.

Hard 256 ppm East Midlands Anglian Water
Your reading
256
parts per million
Soft
Moderate
Hard
Very hard
0100200300400+

What this means for your home

Based on 256 ppm in Daventry (hard water).

  • Significant limescale buildup in kettles, pipes and boilers
  • Soap scum on shower screens and taps
  • Higher energy bills from scale in heating elements
  • Dry skin and dull hair after washing
  • White residue on dishes and glassware
Heat loss
8%
Moderate scaling
Softener salt
£15–25
per year
Worth it?
Yes
at 256 ppm
Suggested for hard water
Whole-house water softener
Best long-term protection for boilers and pipes.
From £600 installed
Shower head filter
A simple first step for limescale on tiles and glass.
From £25
Filter jug or under-sink
Improves taste and reduces kettle scale.
From £20
Softening

Should you soften the water in Daventry?

A verdict and running-cost estimate based on NN11's 256 ppm reading, for a typical 4-person household.

Softener recommended

Water is hard to very hard, so appliance, scale and soap savings typically pay back a softener within a few years.

Recommended size
24k
grain capacity, regenerates ~every 10.5 days
Salt running cost
£15–25
per year (~52 kg salt)
Limescale
8%
est. heater efficiency loss. Moderate scaling
Soap saving
Moderate
Noticeable saving: soaps lather more easily, cutting detergent use.

Appliance impact at 256 ppm: noticeable: boiler/dishwasher life cut without descaling. Sized for a 4-person home; regenerates roughly every 10 days (estimate). Figures are conservative estimates and vary with household size and usage.

Water quality details

Hardness data for NN11

Sourced from Anglian Water's published water-quality reports and public records.

Hardness measurements

Parts per million (ppm CaCO₃)256
Degrees Clark (°Clark)17.9
Degrees French (°fH)25.6
Degrees German (°dH)14.3
Calcium (mg/L Ca²⁺)103

Supplier and area

Water supplier Anglian Water
Region East Midlands
County Northamptonshire
Hardness band Hard
UK average 207 ppm
Visit Anglian Water page
Official source
Anglian Water Services Ltd water-hardness report

Read the hard water explainer then use the linked postcode checker to confirm if you are in a hard water area; the region averages very hard.

Nearby

Other areas near Daventry

NN10
Rushden
255ppm
Hard
NN12
Towcester
257ppm
Hard
NN13
Brackley
258ppm
Hard
FAQ

Common questions about NN11

What is the water hardness in NN11 Daventry?
The water in NN11 Daventry has a hardness level of 256 ppm (parts per million) calcium carbonate, classified as hard. This is 49 ppm above the UK national average of 207 ppm.
Which water company supplies NN11?
NN11 Daventry is supplied by Anglian Water. Anglian Water serves the East Midlands region.
Is the water in NN11 safe to drink?
Yes. Hard water at 256 ppm is safe to drink. Water hardness affects taste and can cause limescale, but it is not a health risk. In fact, hard water contains beneficial minerals like calcium and magnesium.
How can I reduce water hardness in NN11?
For hard water at 256 ppm, a whole-house water softener is the most effective solution. You can also use a jug filter for drinking water, descaling products for appliances, and a shower filter for better skin and hair.
What does 256 ppm water hardness mean?
256 ppm means there are 256 parts per million of calcium carbonate dissolved in the water. This is equivalent to 17.9 Clark degrees, 14.3 German degrees, or 25.6 French degrees. Water above 180 ppm is generally considered hard.
What size water softener do I need in NN11?
For a typical 4-person home at 256 ppm, a 24,000 grain softener is a sensible size. It would regenerate roughly every 10.5 days. Larger households or higher daily use need a bigger unit. These figures are conservative estimates.
How much does it cost to run a water softener in NN11?
At 256 ppm, expect to use about 52 kg of salt a year, costing roughly £15–£25/year. Water is hard to very hard, so appliance, scale and soap savings typically pay back a softener within a few years.

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