9 November 2026 · My Store Admin

How to use and change the filter on the Russell Hobbs Purity Brita kettle (20760)

Last updated 9 November 2026. Written by the Clean Smile Home team. We sell the Russell Hobbs Purity kettle and several other kettles, so bear that in mind as you read. We don't run lab tests ourselves: the setup steps below come from the Russell Hobbs instruction manual and BRITA's own guidance, and test findings come from the reviewers named in the sources at the end.

The short answer

Soak the new BRITA cartridge in cold water and shake it until the bubbles stop, push it fully into the funnel, then fill and throw away two kettles of filtered water. Reset the BRITA Memo on the lid by holding START until all four bars flash twice. Replace the cartridge when the bars run out, roughly every four weeks.

What you're working with

The Russell Hobbs Purity Glass Kettle with BRITA Filter (20760-10) looks like an ordinary glass jug kettle, but the top third is a funnel that holds a BRITA cartridge. You pour tap water into the funnel, it drips through the cartridge into the glass jug below, and you boil the filtered water. The idea is simple: catch some of the hardness minerals before they ever reach the element, so you get less scale floating in your tea and less crust on the kettle.

Here are the parts that matter for filtering:

The funnel. This lifts out with the rim and lid assembly. The cartridge sits in it.
The cartridge. A BRITA MAXTRA-type cartridge, the same shape as the ones in BRITA jugs.
The BRITA Memo. A small display on the lid with four bars and a START button. It counts time, not litres.
The water window. Shows how much filtered water is in the jug, with a max mark.

Key specs at a glance

Spec	Russell Hobbs Purity 20760-10	Where it comes from
Capacity	1 litre (about four cups)	Currys, Argos, Mumsnet and our product listing
Minimum fill	2 cups	Russell Hobbs manual
Power	3000 W	Currys, Argos, Mumsnet
Filter	BRITA MAXTRA cartridge (see the note below on MAXTRA+ and MAXTRA PRO)	Manual, Currys, Argos
Filter reminder	BRITA Memo, four bars, one disappears each week	Russell Hobbs manual
Funnel holds	Around two cups at a time	Mumsnet review
Guarantee	2 years, plus an extra year if you register within 28 days	Russell Hobbs manual
Our price	£41.39 at the time of writing	Clean Smile Home

One thing worth flagging: a few retailer pages list this kettle as 1.5 litres. Every detailed spec sheet we found (Currys, Argos, and Mumsnet's hands-on review) says 1 litre, which matches the box we sell. If you need to boil a lot at once, this isn't the kettle for you, and our best kettle guide covers bigger options.

Which cartridge does it take: MAXTRA+ or MAXTRA PRO?

This is the question we get most, and the sources don't fully agree. The Russell Hobbs manual says to use only BRITA MAXTRA+ cartridges, because MAXTRA+ was the current BRITA cartridge when the kettle launched. BRITA has since replaced MAXTRA+ with the MAXTRA PRO range. Current boxes, according to the Currys and Argos listings, ship with a MAXTRA PRO Limescale Expert cartridge, and Currys sells the MAXTRA PRO Limescale Expert packs as suitable for BRITA jugs and kettles.

In practice, MAXTRA PRO is the cartridge you'll find in shops now, it's the same physical format, and it's what Russell Hobbs puts in the box today. We'd buy MAXTRA PRO. We couldn't find a BRITA page that says in so many words that MAXTRA+ and MAXTRA PRO are interchangeable, so if you have an older kettle and want certainty, Russell Hobbs customer service is on 0345 658 9700.

Within MAXTRA PRO there are a few versions. The two you'll see most:

Cartridge	What BRITA says it does	Who it suits
MAXTRA PRO Limescale Expert	"50% better limescale protection" than the All-in-1/Pure Performance version, plus chlorine and taste reduction	Hard and very hard water areas, which is where BRITA recommends it
MAXTRA PRO All-in-1 (Pure Performance)	Reduces limescale, chlorine and some other substances that affect taste	Moderate or soft water where taste matters more than scale

If you've bought a Purity, you almost certainly live somewhere with hard water. Stick with Limescale Expert.

Before you use the kettle for the first time

Do this once, when the kettle comes out of the box. It takes about 10 minutes, most of which is waiting for water to drip through.

Remove all the packaging, including any stickers or cardboard inside the funnel.
Rinse the jug. Fill it with plain tap water, swirl and pour away. This isn't in every guide, but it gets rid of any dust from the factory.
Take the cartridge out of its foil. If the inside of the packet is damp, that's condensation and normal. Small black specks are carbon from the filter and are harmless, according to the manual.
Soak it. Put the cartridge in a bowl of cold water and shake it gently under the surface until no more bubbles come out. A few carbon particles may float up. That's fine.
Fit it. Push the cartridge down into the funnel until it won't go any further. It should sit firmly and level. If it's loose, the water will bypass the filter.
First flush. Fill the funnel quickly with cold tap water, and top it up as it empties, until the jug reaches roughly the max mark. Pour that water away. Don't boil it.
Second flush. Do the same again and pour it away. After two lots, the cartridge is ready.
Reset the Memo. Press and hold START until all four bars appear and flash twice, then let go. A small flashing dot in the corner tells you it's counting.

BRITA's own instructions for MAXTRA PRO in a jug are the same pattern: soak, shake out the air, fit, then discard the first two fills. The kettle manual says the flush is a "must" before first use, so don't skip it to get a quick cuppa.

Day-to-day use

Filling

Open the lid with the lid lock and pour cold tap water into the funnel. The funnel only holds about two cups at once, so for a full kettle you'll fill it, wait, and fill it again. Mumsnet's reviewer, who tested it in a hard water area of Leeds for four weeks, listed "slower to fill than a standard kettle" as the main downside, and Argos customer reviews say the same. It's the price of filtering. If you're used to filling under the tap and switching on in five seconds, it takes some getting used to.

A few habits that help:

Fill it after you've used it, not when you want a drink. The water is filtered and waiting next time.
Use filtered water within a day. The manual is blunt about this: water is a food and it goes off. Don't leave the same water sitting for days.
Use at least 2 cups. The manual's minimum fill is two cups. Below that, you risk the boil-dry cut-out.
Don't fill above max. Overfilled kettles spit boiling water from the spout. If you've gone over, pour some out before boiling.
Close the lid and press it down so it locks before you switch on.

Boiling

Put the kettle on its base, move the switch to I, and the blue light comes on while it heats. It switches itself off at the boil. You can stop it early by moving the switch to O or lifting it off the base. A bit of moisture on the base after lifting is normal and comes from the steam switch-off, according to the manual.

At 3000 W it's quick once it's full. Mumsnet timed a single cup at roughly 45 seconds. Argos customers rate it 4.7 out of 5 for boiling speed but only 2.5 for noise, so expect a fairly lively boil. Mumsnet's reviewer found it quiet enough, which shows how subjective noise is. If quietness is your priority, read our post on the Russell Hobbs Buckingham Quiet Boil.

Understanding the BRITA Memo

The Memo is the little four-bar display on the lid. People assume it measures how much water has gone through the filter. It doesn't. It's a timer.

When you reset it, all four bars show. That represents the cartridge's four-week life.
One bar disappears each week.
When one bar is left, check you have a spare cartridge in the cupboard.
When all four have gone, a flashing arrow appears at the top. Time to change the cartridge.
A flashing dot in the bottom right shows the Memo is working. No dot means the battery may be flat or it hasn't been started.

Because it counts weeks, it can't tell whether you're a two-cups-a-day household or a twenty-cups-a-day one. BRITA rates a MAXTRA PRO cartridge at about 150 litres in moderately hard water (10 to 12 dH) and says to change it at least every four weeks, sooner if your water is harder or you use a lot. For a 1 litre kettle, 150 litres is about 150 full kettles, or five a day for a month. A big tea-drinking household could get through that faster than four weeks.

So treat the Memo as a maximum, not a target. Signs you need a new cartridge before the bars run out:

White flakes or a film reappearing in the jug or on your tea.
Water starting to taste of chlorine again.
Water draining through the funnel much faster than it did when the cartridge was new.

How to change the cartridge

Unplug the base and let the kettle cool.
Empty the jug and any water left in the funnel.
Pull the old cartridge out of the funnel. It may resist a little because it's a snug fit, so pull straight up rather than twisting hard.
Wipe the funnel with a clean, damp cloth if there's any residue. You can lift the rim and lid assembly off and take the funnel out to do this properly.
Prepare the new cartridge exactly as on day one: soak it in cold water and shake until the bubbles stop.
Push it fully home in the funnel.
Flush twice: fill to about max, discard, repeat.
Reset the Memo: hold START until all four bars flash twice.
Bag up the old cartridge for recycling (see below).

When you refit the funnel, the manual says the flat side should face the handle. If the lid won't close properly, the funnel is usually the wrong way round.

Recycling old cartridges

Don't put them in your household recycling bin. BRITA has run a take-back scheme since 1992, and the cartridges go back to BRITA in Germany where the materials are separated and reused. BRITA lists Tesco, Sainsbury's, Argos, Robert Dyas and some Waitrose stores among its return points, usually at the customer service desk or next to the battery recycling box. It's free. BRITA cites a 2022 lifecycle study saying recycling a cartridge produces 47% less CO2 than incinerating it with general waste. We keep a bag in a kitchen drawer and drop off a few at a time.

Three-year running cost

The filter is the ongoing cost of this kettle, and it's worth being clear-eyed about it. Here's the maths using the prices we found on 9 November 2026. Prices move a lot, especially multi-packs.

Cartridge source	Price	Per cartridge	Cartridges in 3 years (every 4 weeks)	3-year filter cost
Argos, MAXTRA PRO Limescale Expert 6-pack	£39.00	£6.50	39	about £254
Waitrose, MAXTRA PRO Limescale Expert 3-pack	£22.00	£7.33	39	about £286

That's roughly £85 to £95 a year if you change on schedule, on top of the kettle and electricity. Mumsnet's reviewer reached the same conclusion: their indicator was at 50% after three weeks and they expected to buy a cartridge about once a month.

Is it worth it? Honestly, it depends on why you bought it. If you just want less scale in the kettle, a standard kettle plus a monthly descale with citric acid or vinegar costs a few pounds a year and does a similar job for the kettle itself. Our Snowdon guide walks through descaling. What the filter gives you that descaling can't is better tasting water and no scum on top of your tea. In properly hard water areas, a lot of people find that difference is the whole point. Our post on why a BRITA filter kettle helps with hard water goes into the science.

A few ways to keep the cost down without cutting corners:

Buy six-packs or larger. Per cartridge they're usually a pound or so cheaper than singles.
Watch for multi-pack offers around Black Friday and in January.
Unopened cartridges keep for several years if stored sealed between 1°C and 50°C, according to BRITA, so stocking up when they're cheap is fine.
Only boil what you need. Less water through the filter, less energy used.

We'd advise against stretching a cartridge well past four weeks to save money. BRITA's guidance is to change at least every four weeks, and an exhausted cartridge just lets hard water through, so you're paying for the slow fill without the benefit.

Cleaning and looking after the kettle

Outside: unplug, let it cool, and wipe with a clean, damp cloth. Keep the connectors on the base and underneath the kettle dry.
Funnel: lift out the rim and lid assembly, lift out the funnel and wipe it with a damp cloth. Don't wipe or scrub the cartridge itself; the manual specifically says not to.
Glass: the filter reduces scale but won't remove all of it. Mumsnet saw no visible limescale after almost a month in a hard water area, which is a good sign. One Argos reviewer complained of cloudy glass after the first day, so results vary with water and use. If the glass does cloud over, a descale with a kettle descaler or a citric acid solution will clear it. Take the cartridge and funnel out first and rinse well afterwards. The manual doesn't give its own descaling routine, so follow the descaler's instructions.
Going away: if you won't use the kettle for a few days, empty and rinse it. When you're back, flush the cartridge again (fill and discard) before boiling.

Common problems and fixes

Water drips through very slowly

Some slowness is normal, and a brand-new cartridge often runs slower than one that's bedded in. If it's crawling, BRITA lists three causes: you're not using a genuine BRITA MAXTRA PRO cartridge, the cartridge isn't pushed fully into the funnel, or it wasn't prepared properly. Take it out, soak and shake it again to clear trapped air, and refit firmly.

Water runs straight through very fast

Usually the cartridge isn't seated and water is going round it rather than through it. Push it down until it stops. If it still gushes, the cartridge may be exhausted or the wrong type.

Black specks in the water

Those are carbon particles from a new cartridge. The manual calls them harmless. Another flush or two usually clears them.

The Memo display is blank

The Memo has its own small battery. If nothing shows when you press START, the battery has likely run out. The manual explains that you can prise the Memo out of the lid with a screwdriver in the notch above it when the kettle is being disposed of, but it doesn't describe replacing the battery. Contact Russell Hobbs if the display dies during the guarantee period. The kettle itself keeps working; you'll just need to note the change date on your calendar.

The kettle switches off before boiling

That's the boil-dry cut-out, usually triggered by too little water. Unplug it, let it cool and the cut-out resets itself. Always use at least two cups.

It spits from the spout

Overfilled. Pour some out to below max.

The lid won't close

Check the funnel is seated with its flat side towards the handle and that the cartridge is pushed fully down.

Who the Purity suits, and who it doesn't

Hard water and you hate the scum on tea: this is exactly what it's for.
One or two people, mostly hot drinks: the 1 litre size is fine, and filling ahead becomes a habit quickly.
You already use a BRITA jug: you're used to the routine, and you'll be buying the same cartridges.
A big household boiling for pasta and hot water bottles: the capacity and fill speed will frustrate you. Look at a 1.7 litre kettle like the Russell Hobbs Snowdon and descale it regularly instead.
You want temperature control for green tea or coffee: the Purity only boils. See the Ninja Perfect Temperature kettle or the Cuisinart glass temperature kettle.
You want a glass kettle without the filter cost: the COSORI glass kettle is cheaper to run. Our post on glass kettle pros and cons is worth a read.

Tips from living with a filter kettle

Put a recurring reminder on your phone for every four weeks as a backup to the Memo.
Write the change date on the cartridge with a marker before fitting it.
Fill the funnel straight after making a drink. By the time you want the next one, it's full.
Keep a spare cartridge in the cupboard. Running out means either hard water or a trip to the shop.
Don't put hot water in the funnel. Use cold tap water only.
Register the kettle with Russell Hobbs within 28 days to get the extra year of guarantee.

Our verdict

The Purity does what it promises if you look after the cartridge: prepare it properly, change it on time, and fill ahead. Most of the complaints we've read come from people who expected it to fill like a normal kettle or who were surprised by the cartridge cost. Go in knowing it's about £85 to £95 a year in filters and a slower fill, and in a hard water area it's a pleasant kettle to live with. In a soft water area, we'd save the money and buy a standard kettle.

Frequently asked questions

How often should I change the filter in my Russell Hobbs Purity kettle?

Change it at least every four weeks, which is when the four bars on the BRITA Memo run out. BRITA rates a MAXTRA PRO cartridge at about 150 litres in moderately hard water, so a busy household or very hard water may need a change sooner.

What filter does the Russell Hobbs Purity 20760 use?

It takes BRITA MAXTRA-format cartridges. The manual names MAXTRA+, which BRITA has since replaced with MAXTRA PRO, and current boxes ship with a MAXTRA PRO Limescale Expert cartridge according to Currys and Argos. MAXTRA PRO Limescale Expert is the one to buy for hard water.

How do I reset the filter indicator on a Russell Hobbs Brita kettle?

Press and hold the START button on the BRITA Memo until all four bars appear and flash twice, then release it. A flashing dot in the corner shows it has started counting down the four weeks.

Do I need to soak a new Brita kettle filter?

Yes. Submerge the cartridge in cold water and shake it gently until no more bubbles come out. This removes trapped air so water flows through the filter properly rather than around it.

Why do I have to throw away the first two kettles of water?

Flushing clears loose carbon particles and settles the filter media. Both the Russell Hobbs manual and BRITA's own guidance say to discard the first two fills from a new cartridge before using the water.

Why is my Brita kettle filtering so slowly?

The funnel only holds about two cups, so some waiting is normal. If it's much slower than usual, re-soak the cartridge to remove air, push it fully into the funnel, and check it's a genuine BRITA cartridge, which are the causes BRITA lists.

Can I use the Purity kettle without a filter?

The manual is written around always using a BRITA cartridge, and without one the water would pour straight through the funnel unfiltered. We'd keep a cartridge fitted. If you don't want to pay for filters, a standard kettle makes more sense.

What are the black bits in my Brita kettle?

Small black specks from a new cartridge are carbon particles from the filter. The Russell Hobbs manual describes them as harmless, and they normally clear after the first flushes.

Do I still need to descale a Brita filter kettle?

Much less often, but possibly. Mumsnet's tester saw no limescale after nearly a month in a hard water area. If scale or cloudiness builds up over time, remove the cartridge and funnel and descale the jug with a kettle descaler, then rinse well.

How much do Brita kettle filters cost a year?

At the prices we found in November 2026 (£6.50 to £7.33 each in multi-packs), changing every four weeks costs around £85 to £95 a year, or roughly £254 to £286 over three years.

Can I recycle Brita filter cartridges?

Yes, for free through BRITA's take-back scheme. Drop them at return points in stores including Tesco, Sainsbury's, Argos, Robert Dyas and selected Waitrose branches. Don't put them in your household recycling.

How long does filtered water last in the kettle?

Use it within a day. The Russell Hobbs manual warns that filtered water goes off if left standing, so empty and refill rather than reboiling the same water for days.

What size is the Russell Hobbs Purity kettle?

It holds 1 litre, about four cups, according to Currys, Argos and Mumsnet. Some listings say 1.5 litres, but the detailed spec sheets and our stock are 1 litre. The minimum fill is two cups.

Sources

hard water
kettles
Russell Hobbs