Undissolved tablets and residue soap in my dishwasher

Causes and Solutions

• Too much detergent – if you are using loose detergent, cut back on the amount you use, especially if you are not washing a heavy load of pots and pans after Sunday lunch.  For just cups, plates and glasses you probably only need a small amount of detergent.  The only way to be sure is to try out various amounts until you are happy with your dosage.
• Stale tablets – this problem can arise if you use an older product, one that has been hanging around at the back of the cupboard.  These tablets can dry out and the result is they do not dissolve properly.  Also, if there is a possibility that the tablet could have got damp over time, this will have the same effect.
• Powder detergent – if you use this type of product, you must ensure that the soap dispenser is dry, otherwise the powder will not be released properly.
• Programme selection – sometimes tablets will only work well at a higher temperature.  Tablets do not have sufficient time to dissolve completely on a shorter or Eco programme.  You may find you have better results if you use gel caps.
• Quality of detergent – the old adage ‘you get what you pay for’ is just as true for dishwasher detergents as for anything else.  It is better to go for a good quality brand and product that you know you can rely on.  It is more economical in the long run as you will have a better finish and will not have to run the cycle again to get your dishes clean.
• Spray arms – if you have had no problems with your dishwasher detergent in the past but have just noticed this problem, it could be that the spray arms have become blocked and need to be cleaned.  This is a simple process, and your manufacturer’s handbook will clearly show how you should do this.  It could also be that you have something that is too tall in the dishwasher that is stopping the spray arms from rotating properly.  You may be able to hear a slight knocking during the programme if this is the case.  If you are unsure if the spray arms will clear the crockery, spin them manually before you start the machine, as this will give you an opportunity to move the crockery around to give you a good clearance.

General Maintenance

It is a good idea to keep your dishwasher as clean as possible and you should frequently buy one of the many types of dishwasher cleaner and freshener to keep your machine working well.