Is Calgon Worth Using?

Anti-limescale products can help prevent limescale, and limescale definitely damages washing machines, but washing machine detergent already contains protection from limescale. So you shouldn’t really need anything other than the washing machine detergent to protect the washing machine from limescale. However, you need to use the correct amount of detergent to prevent limescale.

So, washing machines can last longer with Calgon if you don’t use the proper dose of detergent. But that doesn’t mean they can’t last longer without it, either – as long as you use good quality detergent, and the correct amount of detergent for the type of water in your area.

What do washing machine manufactures say?

This clearly means that using enough detergent, will not result in limescale that could damage your washing machine. Here’s a different quote from a user’s guide to looking after your washing machine produced by Persil, which goes further –

“One of the things that can damage your washing machine is the build up of scale, particularly in hard water areas. But if you use Persil Automatic (or other detergent) at the correct dosage, you won’t need any additives to help protect your machine from limescale”

So washing machine detergent already contains ingredients to soften the water and protect the washing machine from limescale. If you use a good quality detergent, and the correct dosage for the hardness of your water and the level of soiling on the laundry, you should not need to use anything extra. If you are getting limescale problems, then you probably aren’t using enough detergent.

Calgon softens the water

It’s advertised as a limescale preventer. Technically it is, though it doesn’t do anything different to the softeners in detergent (which they do state clearly now on their website). It simply softens the water, the same as detergent does. In my experience though, as so many people seem to under-dose with detergent, maybe Calgon does a good job of helping such people protect against limescale when they persuade them to use their product.

A potential advantage of using something like Calgon is that you can then use less washing machine detergent. However, this would only make sense if the combined cost of Calgon and the reduced amount of detergent was less than the cost of the full dose of detergent alone.

Can limescale really shorten a washing machine’s life?

Yes, there’s no dispute about that. Limescale can rot seals, and insulate the heating element by completely covering it, but these effects usually take a long time to become a problem. The controversy over Calgon is their insinuation that if you don’t use Calgon, it will shorten the life of your washing machine, which is only true if you don’t use enough detergent.

Also, does limescale really shorten a washing machine’s life as quickly as most people might assume? Consumer group, Which? submitted a complaint to the Advertising Standards Authority, asking it to investigate the claims made in Calgon’s adverts after their tests showed that washing machines do not succumb to masses of limescale and break down if Calgon isn’t used.

Personally, I’ve stripped down many old washing machines that were covered in limescale inside, but were still actually working. The heating element can become covered in it, but many still keep on working as the limescale covering is often quite thin. However, any coating of limescale on a heating element will have an insulating effect. That will reduce the amount of heat released into the water, and increase energy use and wash times.

It can also cause hot spots on the element, which can cause a heater to fail. Limescale is more of an issue in very hard water areas. In areas with soft or moderately hard water, it can take many years for limescale to build up enough to cause a break-down. For most people, it will never cause any breakdowns. Ironically, many modern washing machines just don’t last long enough for limescale to cause a problem unless the water is very hard, and detergent dosage is very low.

In September 2011 Which? also published an article in their magazine entitled, “Calgon’s own research matches Which? findings”. They reported that Calgon themselves have found it takes at least 3 years to show signs of significant limescale damage, by which time you would have spent £170 on Calgon (2011 prices). I think it’s safe to assume this is in hard water areas, so soft water areas would presumably never show any signs of breakdown due to limescale or take much longer.

Do not use in soft water areas

There could be many people using Calgon who have relatively soft water and could therefore be softening the water in their washing machine too much. This is because Calgon has often been advertised in areas with soft water, and their hard water checking tool was “faulty” (see next paragraph) for many years. Apart from being a waste of money, water that is too soft is not good for washing laundry. It can cause excessive soap suds, poor wash results, and even prevent detergent from being dissolved properly.

Check if your water is hard or soft

If you are concerned about limescale, you need to know exactly how hard or soft your water is. For many years, Calgon’s website had a post code checker tool. It checked the hardness of the water in your area by post code. I was initially impressed with this, and even considered linking to it. However, when I entered my own post code I received a full red bar pointing to “hard”, and the following message –

“HARD – We recommend using Calgon in every wash to prevent limescale build up in your washing machine”

As I knew we had fairly soft water, I sent them an email pointing this out, and asking them to look into it. The tool was clearly inaccurate (at least with my post code). Even though they acknowledged receipt of my e-mail and claimed they would look into it, the erroneous advice was still there over 6 years later. Unfortunately, I was left feeling they couldn’t be trusted to advise on whether you have hard water or not.

Fortunately, they’ve now dropped this tool, and just use a UK map with large red areas highlighted. However, when I contacted Yorkshire water to double-check the hardness of my water, they told me that post codes were an unreliable way of accurately determining water hardness.

Free water hardness test kits are available

Although Calgon have an online form that you can fill in to send off for a free test kit, I sent for one through my local water company. Ironically, when mine arrived, it was supplied by Calgon. It consisted of a small strip to dip into the water, which would indicate the hardness of the water. Sure enough, it showed my water is soft. So this at least implies their proper physical testing kit can be trusted.

Summary regarding Calgon tablets (or similar products)

Products such as Calgon don’t do anything that proper washing machine detergent doesn’t do (as long as you use the correct amount), but they do the following –

• Help protect against limescale if you aren’t using enough detergent
• Soften the water, allowing you to use the amount of detergent recommended for soft water in a hard water area

The last effect could potentially save money if the money saved by reducing the amount of washing detergent is greater than the cost of the Calgon (or similar) tablets. I don’t know of anyone who has done the appropriate calculations to determine this, but Calgon claim you could save up to 25% of the amount of detergent required. 25% is presumably the best case scenario. So it depends on how much the tablets cost, compared to how much you save using 25% less detergent. The calculation you need to do is, if you used 25% less detergent but started paying for 1 Calgon tablet in every wash would you save money?

Why do some washing machine manufacturers recommend Calgon?

A few reputable washing machine manufacturers recommend Calgon. Calgon’s website lists 6 (at time of writing) but because some of them are the same manufacturer making different brands (e.g. Electrolux, Zanussi and AEG) there are only really 3. I was initially puzzled as to why, because, if it was really so necessary and useful, surely all brands would recommend it? And conversely, if it really was unnecessary, then surely no brands would recommend it?

Recommending any product to all new customers is likely to be a commercial arrangement, but I can only speculate as to why they do it. They may be recommending it because they know that a substantial percentage of people just don’t use enough detergent. So maybe they would rather people use Calgon tablets, and be more likely to keep their washing machines free of limescale (and working).

If you have hard water

Some people do indeed suffer from problems caused by limescale, and I occasionally come across people who claim to have used good quality detergent, and always used the right amount, but still have limescale problems in their washing machines. This appears to contradict some advice in this article. There’s no way of knowing how accurate their anecdotal evidence is. Possibly they just haven’t used enough detergent, but in the interests of balance, here’s a link to one such case – Limescale problems in washing machine.