3 Reasons Why Kettles Switch Off Before The Water Has Boiled

Sick of lukewarm tea? Here’s why kettles fail to boil and how you can fix it.

When an electric kettle works normally, it automatically switches itself off when the water reaches a certain boiling point. When it switches off prior to the correct time, the three main causes are limescale build-up, a faulty thermostat or a bad kettle design.

So why did your kettle go on a slow-motion strike? Here are the top ways to troubleshoot and fix your kettle.

Read Next: This is why your kitchen tap whistles.

The 3 Reasons Why Your Kettle Switches Itself Off Before Boiling

Truth be told, when a kettle does this it can be near boiling – or far from it. But all such kettles have one thing in common. They all switch themselves off too early. When this happens, you are naturally frustrated and wondering if the kettle has broken somehow. 

Undoubtedly, some electrical kettles are broken but they rarely start boiling and then switch themselves off early. Broken kettles tend not to boil at all or refuse to switch off. But when you have an appliance that starts like normal and then quits before the water is properly boiled, there are three possibilities that you must consider. 

  1. The kettle’s limescale problem has grown so much that it is interfering with the ability of the appliance to function.
  2. The thermostat is faulty.
  3. The kettle was badly designed.

How Do I Know If Limescale Is Causing My Kettle To Switch Off Early?

Limescale is the bane of many caffeine lovers. This mineral deposit is common in hard water areas but it can cause problems no matter where you live. Over time, limescale builds up in appliances that use water like kettles, pipes, and even the washing machine. If the problem is allowed to grow, limescale can interfere with an appliance and even damage it.

How To Recognize Limescale In Your Kettle

Limescale is mostly calcium carbonate and in case you are wondering, it is relatively harmless to consume! But it still makes tea taste bad. However, when your favourite brew suddenly starts tasting off, it is not the only sign that your kettle has limescale. You can also peek inside and look for white or chalky deposits. 

An electric kettle with an exposed element is particularly vulnerable. For some reason, limescale loves to coat the element. Limescale can be light or severe, appearing as a pale film over the element or even like sea barnacles. The latter is a dead giveaway that your kettle has a serious limescale problem. Kettles with a hidden element often develop limescale on the metal floor and walls.

3 Reasons Why Kettles Switch Off Before The Water Has Boiled

Limescale on a garden tap

How To Descale Your Electric Kettle

Limescale might sound like a serious problem. But the truth is that it is often the easiest of the 3 top reasons to fix. Your kettle can be treated at home for limescale and you can also do routine maintenance to prevent the problem from returning. Here are two ways to banish scale and get a tasty cup of tea.

Method 1 – Use A Vinegar Solution

Step 1: Check your kettle’s instruction booklet to see if you can use a vinegar descaling solution (which is a very common method and often mentioned by manufacturers).

Step 2: If you can use a vinegar solution, follow the manufacturer’s suggested ration to mix a blend of water and vinegar. But you can also use a 1:1 ration (one cup of water for every cup of vinegar).

Step 3: Unplug the kettle.

Step 4: Carefully pour the solution into the kettle. You can choose to leave the kettle like this overnight. The acidic nature of the solution will do its magic and the limescale will be easy to remove the next morning.

Step 5: Alternatively, after you have poured the solution into the kettle, you can plug the kettle back in and switch it on. 

Step 6: Considering the problem, the kettle might not boil normally but repeat the process until the solution boils.

Step 7: Let the kettle stand for an hour. The vinegar solution will now tackle the limescale in earnest.

Step 8: After an hour had passed, remove the solution and give the kettle a good rinse inside. Make sure the vinegar is completely removed. This might take a couple of rinses.

Step 9: Take a clean cloth and make sure it is damp. Wipe the inside of the kettle to remove the remaining limescale.

Step 10: Run a test cycle to see if the removal of the limescale has fixed the problem. If so, the kettle will switch off only when the water is properly boiled. 

Method 2 – Use A Lemon
3 Reasons Why Kettles Switch Off Before The Water Has Boiled

Step 1: Check your kettle’s instruction booklet to see if you can use lemon juice to descale your appliance.

Step 2: Take one lemon and squeeze the juice into roughly 1 and a half cups of water. 

Step 3: Fill your kettle with the solution and heat until the liquid boils.

Step 4: Once the solution boils, you can turn off the kettle and let it sit for an hour.

Step 5: After an hour, pour out the mixture and rinse the kettle until all the lemon juice has been removed.

Step 6: Wipe the inside of the kettle with a damp cloth until all the limescale is gone.

Step 7: Run a normal test cycle with water to see if the removal of the limescale fixed the kettle’s tendency to switch off too early.

How Do I Know If The Thermostat Is Responsible?

A kettle’s thermostat is directly connected to when the appliance switches itself off. When a thermostat works correctly, it switches off the power once the water has reached boiling point. If the thermostat is faulty in some way, it could trigger an early cut-off. 

Apparently, a faulty thermostat is behind most cases of kettles that switch themselves off too early. This is not really good news because the thermostat has to be replaced. Often it is better just to buy a new kettle. 

To know whether your thermostat is faulty, one must take the kettle apart. This can be dangerous or go against a kettle’s warranty. Rather contact your manufacturer or a qualified repair company to have a look if you suspect the thermostat is wonky.

How Do I Know A Bad Design Is Responsible?

At the end of the day, if you suspect a bad design, you have two options. Have an experienced electrician confirm it or get a better brand kettle. It does not take a lot to see the signs of a bad appliance. Chances are that a poor design is behind your troubles if the kettle was cheap, gives other problems, has no warranty, and the brand is not well-known or lacks a good track record. 

A Quick Summary On Kettles That Switch Themselves Off Too Early

  • The 3 most common causes are limescale, a bad design or a faulty thermometer.
  • Limescale can be removed at home.
  • A bad design and faulty thermometer might not be worth fixing and it’s best to replace the kettle.