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Do washing machines live longer with Calgon?

Washing machine with limescale

The heap of pointless products grows: we can’t find any persuasive proof that ‘washing machines live longer with Calgon’. Why are we sucked into buying products from manufacturers that won’t back up their claims?

Advertisers love exploiting fears. A key brand positioning tactic is to magnify a problem and then present your product as the solution. And that’s exactly what seems to be happening here.

The limescale science

Calgon claims that limescale makes washing machines break down and die early, and that its tablets make them ‘live longer’ by preventing this alleged cause of premature death. But this hinges on a shaky premise: does limescale really shorten the life of your washing machine?

After simulating three years of washing in hard water, but otherwise normal conditions of three loads a week at 40°C, we asked an expert with 17 years’ experience to inspect our washing machines for damage. Calgon kept the inner parts spotless, but the thin layer of limescale that had built up without it wasn’t enough to affect performance.

Our expert believes that it would take six to eight years of washing in particularly hard water before a machine would need attention for limescale build up. Plus, not even this would necessarily lead to the washing machine breaking down. And by this point you’d have spent £295 on Calgon tablets – enough to buy yourself a new machine.

Our ASA complaint

We’ve submitted a complaint to the Advertising Standards Authority (ASA) about Calgon’s claims, but there’s a wider issue. Why do we willingly accept the claims made by brands and manufacturers? And why do we think they’re doing us a favour by selling us their products?

Calgon may well have watertight evidence that one tablet per wash somehow extends the life of your machine. But no such evidence exists in the public domain, and the ‘research’ held by Calgon won’t be released to us for reasons of commercial sensitivity.

According to Calgon’s press office, the studies conducted were for internal use only – the results were never meant to be seen by current or potential customers. So how can Calgon possibly justify the claim that its product is solving a problem if it won’t prove that the problem exists? And with no evidence made available, why do we pay money for a product that can’t be justified to us by its own manufacturer?


My washing machine was bought in 1982 and I have never used Calgon or any similar product. It is still working well.

I live in a hard water area and must have spent a fortune on kettle descalers.

I have found allowing the lime scale “flakes” to stay in the kettle keeps the actual limescale build up on the element to low levels – I often repair friends kettles (replacing elements) – most use kettle descalers.

I’ve postulated that what happens in my kettles is the new scale is more “attracted” to form on the loose limescale than on the element – probably due to the greater surface area of the loose scale as I think it is deposited uniformly on both element and loose scale. The kettle filter stops the loose scale appearing in the coffee.

Similar to Wavechange, my Washer is a 1983 Hoover Electron 1100. Fair enough, I live in what was traditionally known to be a soft water area, although I understand that with the “water grid” we are now supposed to be quite hard in this area, and certainly my kettle now furs up slowly which it never used to.

I use the washer for 4 or 5 loads a week. I have a “wash day” and I start with the boil wash (“Whites”) for the kitchen roller towels, the dishcloths, the tea towels and any white bathroom towels I’ve used that week. Then I do a couple of loads on “Whites `Economy” – which is about the nearest to modern 60 degree washes – for my bed linen and coloured towels, underwear and clothes such as shirts which are colour fast. Lastly I do the “non-fast coloureds” or 40 degree wash(es).

My theory is that using non-bio detergents and doing several hot washes each week probably keeps the machine clear of scale, slime, mould and all the other things that we are now always being urged to buy to maintain our machines.

I could be totally wrong, but certainly in almost 28 years my washer has never broken down so something other than Calgon has given it a long life?!

Richard – I think you could be right. Limescale is more likely to build up on a rough surface such as existing than a smooth element. I once met a lab technician who removed limescale from lab water stills by switching them on for a minute or two without any water. The limescale coating cracked and fell off. His theory was that brief e severe overheating was less damaging than continuous overheating resulting form a thick coating of limescale.

Dave – Your washing machine deserves a Which? award for reliability. I’ve had to fit a new motor and pump to mine, so I would not be eligible to enter.

Oops. That should read:
…rough surface such as existing limescale rather than a smooth element.

Wavechange: Thanks – in fact I already contributed (as I think you did) to the convo last year about long lived appliances, in view of my 57 year old vac that’s still working fine, my 28 year old washer, my 32 year old boiler, my 34 year old kettle and various other appliances. Even my last TV, the first I ever had, lasted from 1991 until this January (20 years) and it’s still working fine in a friends house now, but the Remote Control receiver on it was damaged by using a CFL light bulb near to the set so I bought a new one in a sale last December.

Personally I think that longevity in appliances comes down to careful use, not ignoring small signs that something isn’t quite right and buying a good product to start with, rather than a cheap one or one that is uber-fashionable but made for fashion not for quality.

My gut feeling is that none of us needs any of these products like Calgon at all if we simply use things properly to start with.

The greatest difficulty in modern times is that it’s virtually impossible to buy anything that the manufacturers want to last beyond about 2 years at best.

I’m drifting well off topic, but thanks again Wavechange

Dave – I remember the conversation, but I don’t think you have had a mention in Which? magazine yet. I agree with your off-topic observations, though I feel that luck can be a major factor in longevity. The heater in my old washing machine has survived without use of Calgon etc, yet my kettle which was regularly descaled failed after less than two years. (Both were made by Philips)

My failed kettle and the one that has replaced it have the element below the shiny stainless steel base. The limescale does not build up near the element and maybe the same principle could be used for washing machine heaters.

I’m still trying to find out the active ingedient(s) of the current UK version of Calgon, since I believe it has changed to provide a more environmentally acceptable product.

“Buy this insurance, just in case something might ever happen to you”, “buy this product to keep bears out of central london”

Is this not a marketing technique? Create a situation that doesn’t exist then present the solution as your product?

Beware specious marketing, thankyou Which? for helping us to navigate round this

Simon says:
26 May 2011

I’ve had to replace my heating element once due to limescale build up, after about 5 years of weekly use. It only cost around £100 to have it replaced though, so surely I’d have spent more on Calgon in that time?

Actually – two of the three washing machines I’ve bought since 1970 had perfectly good heaters when they broke down for other reasons and were replaced as they were too old to get spares, Never used Calgon in either and I live in a hard water area. My current one is just over 6 years old.

The real issue is the price versus the minor build-up of limescale – abd as this article shows, it’s just not worth it. Even then, it should only be considered for very hard water areas – and how many of us live in them?

One of Which’s more useful research reports.

I don’t think it would be difficult to design washing machine heaters so decrease limescale build up. Compact high power heaters such as that shown in the photo are not a clever idea.

Calgon is a water softener so will cut down the amount of detergent needed in hard water areas.


May I ask what experience and qualifications you have to make the statement ” I don’t think it would be difficult to design washing machine heaters so decrease limescale build up” in domestic washing machines. Exactly what change in design would you make?

Compact high powered elements are designed to ensure the water is heated rapidly in the small volumes required in modern domestic washing machines. What would your cleverer idea be?

Though Calgon is a water softener – much (most?) detergent is in sachet form for washing machines so cannot be changed easily – and it is advertised not as a water softener but as a lime scale preventer as the article says.

I don’t use Calgon though I do live in a hard water area called London.

Actually there are models available which have titanium heating elements which stop both limescale build up as well as corrosion.
I’ve never used Calgon and never will. I only know of 1 person who does use the stuff and I’ll certainly be letting them know about this Which? report.

Hello Richard (the first), try to keep it civil is you can – people needn’t be experts to make suggestions. Remember our Commenting Guidelines explain, try and be considerate of others and the Conversations will be much smoother. Thanks.

Richard – I don’t think that this is the correct forum to get into technical discussions or to require details of qualifications and experience to support messages we post.

One of my thoughts was to change the change the surface coating of heating elements to prevent limescale adhering. Don has pointed out that this solution is already in use. I was unaware of this, so thanks Don for letting us know.

John R says:
27 May 2011

I used a Calgon substitue when living in Bromley (Thames Water), and it did help the washing machine, kettle & bath (no scum marks). Now I’m in Edinburgh, the water is so pure, you could top up your car battery with it (if you could anyway).

I think it is the case that if the wash is done at 60 degrees or higher, scale deposits a lot more- perhaps this is a criterion for whether Calgon is appropriate?

Gill says:
27 May 2011

The first time I saw the advert for Calgon my reaction was simple… if I decide not to use Calgon in every wash, the money I save will pay for a new washing machine… my last machine lasted nearly ten years and no, it was not all ‘furred up’ …it died because it was used at least twice every day! poor thing.

Philip says:
27 May 2011

I have just checked and an average price seems to be about £5 for fifteen tablets. Our washing machine does at least one load per day. £5 / 15 =33p per wash. In five years thats £600 – more than enough to buy a new machine not just a new element. Utter waste of money. While I’m at it another pointless product is the £15 experian credit report. Why would you want that??

Barbara says:
27 May 2011

Have tried Calgon but vinegar is slao good as a descaler. It is old fashioned but it can be used for so many things . Old fashion it may be but so much cheaper. I have had only 3 washing machines in my lifetime they broke down for other reasons tham limescale build ups. I use vinegar once or twice a year. The bulds seem to stem from the fabric conditioners we use, lee is more where they are concerned.
The main solution seems to be invest in a good machine initially which should last longer.

Dave in Peterborough says:
27 May 2011

My washing machine is over 10 years old and I do a low temp wash once a week.
During that period I have used Calgon or supermarket-own-brand powders/tablets to tackle the limescale problem. Of course I don’t know if they work but then I don’t know that they don’t. I am aware that there is a limescale problem here because of the affect on taps and showers in the bathroom.
Your research is interesting because I would be happy to save the money if I don’t need to buy Calgon or similar. However, despite your assertions, I’ll probably keep going at least as long as my machine lasts (come and inspect it if you want).
I’m a bit dubious about your statement of not spending the money in order to save £295 for a new machine. I believe in conservation rather than a throway society.
I’d like more news of this issue as and when the ASA and Calgon make statements about it, prefrably in the magazine rather than online.

Patricia says:
27 May 2011

Ever since I bought my first washing machine about 27 years ago, I have always used a water softener product in every wash, albeit almost never Calgon, which is prohibitively expensive! The reason I have done so is to save money on washing products, as the water softeners are cheaper than washing liquids/powders. If it looks after the machine as well – double the benefit.

Gerry says:
27 May 2011

I feel duped now by the manufacturers of Calgon – I use the liquid which is hugely expensive as the tablets didn’t break down in my washing machine. I too live in a hard water area and was even persuaded to pay a fee for the first time this year for insurance – the first 5 years were free. When supplies are run down I will not be buying any more.

Dr. Guptagombrich says:
27 May 2011

Which is recommending Calgon for years. What should I think now?

washerman says:
27 May 2011

Limescale is much less of a problem nowadays, a combination of cold water fill, low water levels, low temp washes and new detergents cause bacteria to build up inside the drum in the form of smelly grey/brown/black sludge,

Good point washerman. I’d also add to that; all washing machines need to have a maintenance wash run on them every month or so. It’s basically a 90’C cycle with no laundry in the drum but a little detergent. This should rid your machine of any musty smells and any bacterial build up you can see.

Don’s solution is a good way of sorting out the problem, but nasty smells are unlikely if the machine is used on a normal 60′C cycle washing once every week or two. Washerman is absolutely right about the causes and might just have some first hand experience.

I’ve used Calgon for a couple of years. They do seem to reduce the amount of detergent used and stop the machine smelling by stopping the crud building up. Any hints on how else to get rid of smalls on machines?

Mark, the smell is usually caused by a bacteria build-up in the rubber door seal. The easiest thing to do (apart from a regular maintenance wash) is to plop some bleach onto a cloth and wipe the seal all over and in the folds of the rubber. This should kill the bacteria and stop the smell. it’s best to rinse off the bleach before too long, not because it will damage the rubber but more because you may forget to wash it off and wonder why there are bleaching stains on your next load of washing

Mishka says:
17 June 2014

I use a Washing Machine cleaner when it starts to smell and put a bit of it on a cloth first and wipe the door and seal with it. I also take out the tablet drawer and wipe it over and clean the recess. The instructions on the bottle say to do this, then put the remainder of the cleaner in the detergent dispenser and run a hot cycle. So far so good!

margaret Lawrenson says:
27 May 2011

Our water is very very hard and often causes ‘scummy’ deposits on the washed clothes. Calgon seems to prevent this. However I save a lot of money by using Calgon powder – and only about half the recommended dose. The powder is about 1/3rd the price of the tablets.

27 May 2011

Thank you so much WHICH. I have used Calgon in virtually every wash for many many years and would have carried on too. we live in the South and have very hard water, so after seeing the Calgon adverts we ‘knew’ we hda to spend a fortune using a Calgon tablet for every wash.
Once this packet has been used we will never buy it again and will make sure we tell our friends and family also.

Nancy62 says:
27 May 2011

I lived in a hard water area for 6 years, I found using by using calgon I could halve the amount of washng powder required, what a waste of money, my machine expired soon after moving back to a soft water area.