Washing machine limescale build up and removal, causes and cures

Washing machine limescale build up and removal

Understanding the causes of washing machine limescale build up and removal techniques can prove to be vital if you are dependent on a hard water supply. A salient feature of hard water is the fact that this type of water will contain magnesium and calcium in higher percentages than you would normally expect to find. The problem here is that trace amounts of these minerals are left clinging to any container or surface that the water comes into contact with. Limescale is a distinctive side effect of hard water and visually exhibits as a whitish, scaly deposit that is left behind. Every time hard water passes through your washing machine, these deposits are left behind in the washer drum, hose, pipes, seals, and various other parts.


Limescale deposits are not very easy to remove owing to the fact that this is essentially a hard deposit with a high mineral content. These deposits primarily consist of calcium carbonate and with some effort it is possible to scrub away such types of deposits. Practically however, the effort that such an operation would require is likely to leave ugly scratch marks on the interior surfaces of the washing machine. A more reasonable solution would be to expose this type of mineral deposit to an acidic solution. Any solution with a high acidic content has the ability to dissolve calcium carbonate. However, in order for this technique to have the desired effect, any limescale deposit should be exposed to the acid for a reasonable period of time. Simply washing any limescale deposit with an acidic solution will not be effective enough. For the complete removal of hard mineral deposits from your washer’s interiors with an acidic solution, the recommended period of exposure is generally considered to be 30-60 minutes.

In cases where your machine has been badly affected, you will be required to clean out certain components manually to ensure the complete removal of any washing machine limescale build up.

Cleaning the Washing Machine Soap Drawer

One area of your washing machine that is particularly susceptible to problems related with limescale deposits is the soap drawer. Therefore, it is necessary that you pay adequate attention to the cleaning of this component of your washer. The priority area here is usually the water jets that are responsible for forcing water into the soap drawer and not the container where the conditioner or detergent are normally placed. A common issue here is that these nozzles (jets) are extremely vulnerable to limescale deposits and other bacterial build ups that can completely block them.

Cleaning the soap drawer effectively is a necessary step if you make use of hard water for your laundry. One good aspect in the design of these drawers is the fact that they may be removed and replaced without any great difficulty. Consequently, the process of cleaning out the soap drawer remains virtually the same for all washing machines regardless of differences in brand or model types. Invariably the soap drawer will have a release switch at the back of its cavity. Simply reach into the drawer, depress the switch and pull the soap drawer towards yourself. If there is no release switch, applying a slight amount of force is enough for this drawer to come loose.

After the compartment has been removed, disconnect the siphon at the rear end of the drawer. The drawer should be cleaned vigorously with the aid of warm water and a good firm brush. Avoid cleaning this compartment with a dishwasher as this could cause irreparable damage. Most dishwashers utilize water that has been heated to at least 140 degrees which could permanently warp the plastic of the soap drawer. As a result, it may no longer to be able to fit back in its cavity.

Cleaning The Washing Machine Detergent Dispenser Compartment

After the soap drawer has been washed, it is necessary to turn your attention to the detergent dispensing compartment. Prepare a cleaning solution by diluting high quality bleach with warm water. (Bleach is highly effective in dispelling hard mineral deposits and also provides a strong anti bacterial effect.) You may use a dish washing brush with firm bristles to apply the cleaning fluid to the compartment. Brush the compartment vigorously with the dilute bleach. Make sure you are especially thorough while cleaning the corners. They are generally hotspots for bacterial growth and mineral deposits.

You can then turn your attention to the dispensing jets located at the top of the compartment. Quite often, limescale deposits and other solid residue can be visually observed to be blocking these jets. If these deposits are not removed periodically, they may become permanently stuck to the jets and you may need to replace the entire assembly. Cleaning the nozzles can be a relatively simple task with the brush. Simply push the bristles into the jet nozzles to dislodge any sediment that may be trapped.

Following the completion of the cleaning process, the soap drawer may be fitted back in place.

Dealing with Limescale Deposits Inside The Washing Machine


One frequent issue related to limescale deposits is the effect it may have on the washing machine air bell. This is a small device found inside the pressure switch that is connected to the pressure switch hose. In case of significant mineral deposits, this air bell may get clogged, which can interfere with its regular functioning. In most cases, this represents the maximum damage that can be caused to a machine as a direct result of limescale deposits.

However, this condition can be exacerbated if you are in the habit of running your washing machine in its energy saving mode. Frequent low temperature washer (40 degrees and below) and the exclusive use of liquid washing machine detergents or color safe detergents can increase the likelihood of limescale related problems. These types of detergent do not include any form of a bleaching agent that can help sanitize and deodorize your washing machine. A factor that should be considered here is that most washing machine detergents include many biological or chemical agents that are capable of dissolving any limescale deposit, but they require a high temperature for proper activation. 

Most boxed powder detergents include components called 'builders' that are perfectly capable of neutralizing the effects of limescale. Using these products in their recommended doses can be particularly effective in tackling limescale build ups.

One of the best methods of ensuring the peak performance of your washing machine is to run a monthly maintenance hot wash that thoroughly cleans out all the interior surfaces of your machine.

How to descale a washing machine with the maintenance wash

Understanding how to descale a washing machine is important, and the maintenance wash is one technique that can provide you with an effective solution. Primarily, this type of wash is used to descale your machine if you are using hard water for your laundry. The maintenance wash should be performed using the maximum heat setting available on your washing machine. At a minimum, the water temperature for this process should be 140 degrees Fahrenheit, although selecting a temperature range between 194F and 203F is far more effective. At these temperatures, all the components of your detergent are properly activated, which ensures the most potent descaling action. It is also necessary to make use of a powder detergent that includes a bleaching agent. Biological washing machine detergents are also a good choice as they contain enzymes that have the ability to break down any mineral deposits. The maintenance wash is a high temperature empty wash and you should not add any clothes while you are running this program. Running an empty maintenance wash remains one of the best ways of dealing with washing machine limescale build up and removal.

Detergent Components that deliver the best cleaning with hard water

A key component of any detergent is a Surfactant, also referred to as a surface active agent. This is generally an organic chemical that is responsible for altering the basic properties of water in order to optimize the cleaning process. One typical action is to lower the natural water surface tension which helps loosen most types of residue. There are various classifications of surfactants that are used by detergent manufacturers. However, there are certain types of these organic chemicals that are more suited for use with hard water. Nonionic surfactants such as alcohol ethoxylates will not develop an electrical charge when mixed with water. Typically, they produce fewer suds and their cleaning efficiency is not affected by hard water. Detergents with these surfactants are also less likely to precipitate out of solution and result in the formation of soap scum (a semi solid soapy residue).

 Another standard component in detergents is Builders. They are primarily responsible for lowering the mineral concentrations in water (basically, they soften water). Builders such as phosphates, sodium citrate or zeolite (sodium aluminosilicate) are probably the best ingredients to use with hard water. Sodium silicate and sodium carbonate are also 2 popular builder used in detergents, but they have a tendency to cause precipitation in hard water.

Using a commercial washing machine descaler

You may also decide to use a commercial washing machine descaler if you are particularly troubled by limescale deposits. These descalers are freely available in the form of a powder or tablets, and can prove to be extremely effective in dissolving any limescale deposits that have built up in your machine. This increases the overall efficiency of your washer and promotes a trouble free performance.                      

Generally, the washing machine descaler is added to the washing machine tub. You are then required to select the main wash cycle. Do not add any laundry while you are running this program. The descaler works by dissolving any existing limescale deposits as well as any soap or detergent residues that have been left behind in your machine. Commercial Descalers will also include a strong anti-bacterial agent and can help deodorize your washer. They are particularly useful in eliminating limescale deposits from various machine parts including the interior surfaces, wash drum, coils, pumps, pipes, and hoses. These descalers are quite powerful and you are only required to use them once a month in extreme cases. Under normal circumstances, you would use this type of product once every 3 months.

In addition to traditional descalers, you will also find limescale prevention products that may be added to your detergent during a wash program. This class of limescale preventer usually neutralizes any Magnesium or Calcium salts that are present in your water supply. Apart from 'softening' the water, they also have an added advantage of reducing the amount of detergent required for each wash. When used with a new appliance they can reduce your detergent use by more than 60%. Depending on the levels of mineral deposits in your water you are required to add between 25 grams and 75 grams of this product per wash.

Commercial water conditioners are also available that may be added directly to the washing machine drum. These products generally work on the principle of ion exchange to neutralize any mineral content and will help soften the water in your machine.

Simple Solutions to tackle washing machine limescale build ups

A basic remedy to tackle limescale build ups is to fill your washing machine drum with warm water. Depending on the concentration of stains you can add between 2 to 4 cups of virgin white vinegar. Leave this solution for at least 2-3 hours before draining away.

Any cleaning product that contains acids such as sulfuric acid, phosphoric acid, or hydrochloric acid can be extremely effective in dealing with limescale deposits. These acids exert a potent dissolving action on these deposits and have the ability to break down even the toughest deposits. Products with these acids are most suitable when the interior surfaces of your washer are constructed from acrylic or enamel.

You can add a bottle of white vinegar while running a high temperature empty wash. This can prove to be effective in descaling the machine drum and hose. You can run this wash once every 1-2 months to keep mineral build ups at bay.

You can make your own descaling solution at home by mixing in 50% pure white vinegar with 50% fresh lemon juice. This creates a natural, acidic solution that can be effective in dissolving mineral deposits. Pour out this solution into a spray bottle and soak the inside of the machine drum with this solution. Let the acid work on the deposits for 30 minutes before scrubbing with a stiff clothes brush to break away any hard set deposits. Wash away the solution with clean water.

Fill a spray bottle with 100% white distilled vinegar. Drench the insides of your washing machine with the vinegar paying close attention to areas such as the rubber seal where mineral deposits can be quite significant. Let the vinegar stay in contact with these deposits for at least 30 minutes. The acetic acid in the vinegar will then be able to effectively dissolve any solid mineral deposits. Sprinkle baking soda across the vinegar soaked areas of the washer. Scrub these areas with a firm dish brush or scrubby to gently break away any limescale build ups within your machine. Finally, rinse out your machine with clean water.


Disclaimer: The information provided has been prepared as a guide only and the steps taken are likely to vary for different appliance models. We strongly recommend using a qualified engineer to undertake major repairs and fault finding.


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