BRITA Approved Partner
Water hardness & BRITA filter checker
Hard water is one of the commonest causes of coffee machine breakdowns in London and the South East. Check your local hardness, find the right BRITA cartridge and bypass setting, and see when your filter is due.
- Free 1-minute checker
- BRITA Approved Partner
- Water tested on site
1-minute water check
How hard is your water, and when is your filter due?
Enter your postcode and how busy you are. We'll show your typical local water hardness, the BRITA cartridge and bypass setting we'd start from, and how often it should be changed.
I've tested my water
Your result
Most of London and the South East has hard water. That's bad news for an espresso machine: it leaves scale in boilers, valves and group heads. Enter your details and press Check my water.
Email me when my filter is due
We'll remind you a couple of weeks before the change date, and you can book the change in one click.
A guide, not a water test. Hardness is the typical figure for your postcode area, estimated from water company reports, and it varies by street and season. Cartridge capacities are BRITA's published figures for PURITY C Quell ST at the recommended bypass. Water use assumes about 0.18 litres per espresso drink plus a daily flushing allowance. We test your water on site and set the filter to suit.
Why it matters
Water is the cheapest thing to get right, and the most expensive to get wrong
Coffee is more than 90% water. Hard water scales up the inside of your machine; the wrong filter setting can make coffee taste flat or leave the water too aggressive for the boiler. Both end in an engineer visit.
Scale is a slow breakdown
Limescale builds up in boilers, heating elements, valves and jets. It reduces heating efficiency and blocks small passages long before anything stops working.
Taste and consistency
The right minerals help extraction. A filter set for your water keeps shots consistent from the first cup of the day to the last.
Protects your warranty
Our warranty on new machines requires appropriate water treatment. A correctly sized, in-date filter is the simplest way to stay covered.
Filters run out silently
An exhausted cartridge looks the same as a new one. Once its capacity is used up, hard water goes straight into the machine.
ApprovedPartner
BRITA Approved Partner
Water filtration fitted and looked after by BRITA-approved engineers
We're a BRITA Approved Partner. Every machine we install gets water treatment sized to the site, and we keep track of when it's due so you don't have to.
We test your water on site
Carbonate hardness measured at the tap, not guessed from a postcode.
We size the cartridge and set the bypass
Matched to your water and how many drinks you make, so it lasts without letting scale through.
We record the date and remind you
You'll know when the next change is due. Our Silver and Gold service plans include a free annual water filter change.
Any brand we service
Espresso machines, filter brewers and water boilers from the brands we carry parts for.
Postcode guide
Water hardness in London and the South East
Typical range of total hardness by postcode area, in milligrams per litre as calcium carbonate (mg/l CaCO₃) and degrees Clark. Nearly all of our area is hard or very hard, so an espresso machine here needs filtration from day one.
| Area | Covers | Typical mg/l CaCO₃ | °Clark | Band | Main water supplier |
|---|---|---|---|---|---|
| London | |||||
| E | East London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| EC | City of London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| N | North London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| NW | North West London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| SE | South East London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| SW | South West London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| W | West London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| WC | West Central London | 220–350 | 15–25 | Hard to very hard | Thames Water |
| North London edge & Hertfordshire | |||||
| EN | Enfield & Barnet | 260–350 | 18–25 | Hard to very hard | Affinity / Thames |
| HA | Harrow | 250–350 | 18–25 | Hard to very hard | Affinity Water |
| UB | Uxbridge & Southall | 250–330 | 18–23 | Hard to very hard | Affinity Water |
| WD | Watford | 250–350 | 18–25 | Hard to very hard | Affinity Water |
| AL | St Albans | 250–350 | 18–25 | Hard to very hard | Affinity Water |
| SG | Stevenage | 250–350 | 18–25 | Hard to very hard | Affinity / Cambridge |
| HP | Hemel Hempstead | 250–350 | 18–25 | Hard to very hard | Affinity Water |
| LU | Luton | 260–350 | 18–25 | Hard to very hard | Affinity Water |
| Essex & East | |||||
| IG | Ilford | 230–300 | 16–21 | Hard | Essex & Suffolk / Thames |
| RM | Romford | 230–300 | 16–21 | Hard | Essex & Suffolk Water |
| CM | Chelmsford & Harlow | 205–370 | 14–26 | Hard to very hard | Essex & Suffolk / Affinity / Anglian |
| SS | Southend | 225–290 | 16–20 | Hard | Essex & Suffolk Water |
| CO | Colchester | 250–400 | 18–28 | Hard to very hard | Anglian / Affinity |
| CB | Cambridge | 270–350 | 19–25 | Hard to very hard | Cambridge / Anglian |
| South London edge & Surrey | |||||
| TW | Twickenham & Hounslow | 240–320 | 17–22 | Hard to very hard | Thames / Affinity |
| KT | Kingston | 200–310 | 14–22 | Moderately hard to very hard | Thames / SES / Affinity |
| SM | Sutton | 190–280 | 13–20 | Moderately hard to hard | SES Water |
| CR | Croydon | 200–320 | 14–22 | Moderately hard to very hard | Thames / SES |
| BR | Bromley | 240–330 | 17–23 | Hard to very hard | Thames / South East Water |
| DA | Dartford | 240–330 | 17–23 | Hard to very hard | Thames / South East Water |
| Kent, Sussex & the South | |||||
| ME | Medway | 230–350 | 16–25 | Hard to very hard | Southern / South East Water |
| CT | Canterbury | 230–350 | 16–25 | Hard to very hard | Southern / South East Water |
| TN | Tonbridge & Tunbridge Wells | 120–300 | 8–21 | Slightly hard to hard | South East Water / Southern |
| GU | Guildford | 180–320 | 13–22 | Moderately hard to very hard | Thames / Affinity / SES / SE Water |
| RH | Redhill & Crawley | 150–300 | 11–21 | Slightly hard to hard | SES / Southern / SE Water |
| BN | Brighton | 200–330 | 14–23 | Moderately hard to very hard | Southern / South East Water |
| Thames Valley & beyond | |||||
| SL | Slough | 230–330 | 16–23 | Hard to very hard | Thames Water |
| RG | Reading | 230–330 | 16–23 | Hard to very hard | Thames Water |
| OX | Oxford | 230–330 | 16–23 | Hard to very hard | Thames Water |
| MK | Milton Keynes | 250–350 | 18–25 | Hard to very hard | Anglian Water |
Typical ranges, estimated from water company supply-zone reports and supplier statements; many areas are served by more than one company and hardness varies by street. Bands follow Thames Water's scale: soft up to 100, slightly hard 100–150, moderately hard 150–200, hard 200–300, very hard over 300 mg/l. For your exact address, check your water supplier's postcode lookup, or ask us to test on site.
Book it in
Book a BRITA filter change or water test
Tell us about your machine and we'll book an engineer to test your water, fit or change the cartridge and set it up for your site. Your checker result is sent with your message.
- BRITA Approved Partner
- Engineers across London and the South East
- Free annual filter change on Silver and Gold plans
FAQs
Water and filters: FAQs
Can't see your question? Call 01279 452110 or email support@modernstandardservice.com.
Contact the teamHow hard is the water in London?
Hard. Thames Water says all the water in its region is hard, and most of London falls in the hard to very hard range. Much of Essex, Hertfordshire, Kent and Surrey is similar. See the postcode table above for typical figures by area.
How often should I change my BRITA filter?
When its capacity is used up, or within 12 months of fitting, whichever comes first. BRITA says to replace a cartridge no later than twelve months after it was fitted. Capacity depends on your water's carbonate hardness, the bypass setting and how much water you use. Our checker works it out for you.
Which BRITA filter do I need for an espresso machine?
Usually a BRITA PURITY C cartridge, from the C150 up to the C1100, sized to your water and how many drinks you make, with the bypass set for your carbonate hardness. We test your water on site and fit the right one.
What does the bypass setting do?
The bypass sends a set share of water past the softening part of the cartridge, so some minerals stay in for flavour. The harder your water, the lower the bypass. Set it wrong and you either let scale through or strip out the minerals that help extraction.
Do I need a water filter to keep my warranty?
Yes. Our 12-month warranty on new machines is subject to the manufacturer's terms, correct installation, appropriate water treatment and normal commercial use.
Can you change the filter on a machine you didn't install?
Yes, on the brands we service. Book a filter change and tell us the make and model.
Are filter changes included in your service plans?
Our Silver plan includes a free annual water filter change, and Gold includes everything in Silver plus an annual PVI. Compare plans.