The Top 5 Reasons Why Kettles Take Longer To Boil

boiling kettle

Image credit ID 91631298 © creativecommonsstockphotos | Dreamstime.com

Waiting too long for your caffeine fix? Learn more about why your kettle is slow to boil and how to solve the problem.

Five things are usually responsible for a slow-boiling kettle. A kettle will take more time to heat up when more water is added, the appliance has limescale, the water is cold, the lid is not properly closed or the atmospheric pressure is higher than normal.

A kettle that works in slow motion is annoying. Luckily, most of the causes behind this problem is easy to fix. Here’s how.

The Reasons Why Kettles Suddenly Take Longer To Boil

Let’s quickly clarify something. This article deals with kettles that boil longer than they usually do but in the end, they automatically switch themselves off. If your kettle does not switch itself off at all, then you might have to look at the thermostat or the kettle’s lid (we do cover the lid issue in this article).

So what causes a kettle to add extra time to boiling duty? Here are the main 5 reasons. 

  1. You added more water than usual.
  2. You used cold water.
  3. The day has a higher than normal atmospheric pressure.
  4. The kettle has a limescale problem.
  5. There are problems with the kettle’s lid.

How Water Volume Affect A Kettle’s Boiling Time

The average boiling time for an electric kettle is roughly 2 to 3 minutes. However, the actual boiling time is directly linked to how much water you put in the kettle. For instance, water that is enough for just one cup will boil faster than when you fill the kettle completely. 

To be fair, this cause is pretty obvious and not something that most people tend to miss. When you do notice that your kettle is suddenly chugging along in slow motion - and you have added the normal amount of water that you usually do - then something else is wrong.

How Water Temperature Affects A Kettle’s Boiling Time

Here’s another simple reason why kettles suddenly take their sweet time. If you have the habit of filling the kettle from your kitchen’s hot water tap, then you might be used to a faster boiling time. Hot water is already well on its way to boiling point and this shortens the time you have to wait. 

When water is cold, it needs more time to boil. As we mentioned a little earlier, if you have a habit of using the hot water tap, it might be possible that you used cold water this time for some reason. But if you know your mind did not wander and you did use the hot tap, then this is not the problem. 

Find the best quiet kettles.

How Atmospheric Pressure Affects A Kettle’s Boiling Time

pressure gauge

What Exactly Is Atmospheric Pressure?

Here’s a fun fact - air has weight. This weight is called atmospheric pressure because it presses against everything it touches (which is pretty much everything and everyone). Air pressure is greatest at sea level and on hot or stormy days. 

How Can Air Pressure Make My Kettle Boil Slower?

Air pressure can indeed interfere with your kettle’s boiling time. How? Well, the air is alive with molecules. These molecules press down on the water’s surface inside your kettle. In order to reach boiling point, your water must reach the stage where it is basically ready to evaporate. When air pressure rises, the molecules press down harder on the water. This makes it more difficult for the water to reach boiling point. 

Can I Prevent High Air Pressure From Doing This?

Removing high air pressure from the home just to boil a kettle is a little excessive and could also be expensive (you might have to install a ventilation system). All that is basically required on high-pressure days is a little patience. However, if you want to speed things along there is one option. Use the hot water tap to fill your kettle! If you normally use the hot water tap, well… We hear patience is a virtue. 

How Limescale Affects A Kettle’s Boiling Time

What Exactly Is Limescale?

Limescale is a mineral deposit that affects the performance of appliances. Specifically, appliances that work with water like boilers, washing machines, kettles, taps, and even the plumbing. The substance is mainly calcium carbonate and has a chalky or crusty appearance. Limescale is a bigger problem in neighbourhoods with hard water.

How Does Limescale Affect My Kettle’s Boiling Time?

For a kettle to boil normally, the heating element must be in good working order. Unfortunately, the heating element is a favourite spot when limescale accumulates inside a kettle. It then causes the element to struggle and boil the water for longer. Limescale can also affect a kettle with a hidden element. In this case, the mineral deposits pack against the bottom which also interferes with the kettle’s boiling time.

cup of tea with flowers on a matt

How Do I Recognize Limescale? 

How Do I Clean Limescale?

One of the best ways is to use vinegar. Pick the undiluted, natural variety and use the following steps to get rid of limescale in your kettle.

Step 1: Mix one cup of vinegar with one cup of water. Use this ration to mix enough to fill your kettle at least halfway. 

Step 2: If you have time, leave the kettle like this overnight and wipe the limescale off in the morning. 

Step 3: If you want to do this quickly, simply boil the kettle containing the vinegar solution.

Step 4: Pour the vinegar out in the sink.

Step 5: Thoroughly rinse the kettle to wash away most of the limescale and also to get rid of the vinegar smell.

Step 6: Once the kettle is cool enough, take a damp cloth and wipe the inside clean of any remaining limescale. 

If limescale was the problem, then this should return your kettle’s boiling time to normal. It is also a great idea to descale your kettle once a month, even when there are no mineral deposits. This will prevent limescale from building up in the first place.

How The Kettle’s Lid Affects Boiling Time

A kettle’s lid is definitely not for show! It plays an integral part in keeping heat contained to help the water to reach boiling point. If a kettle’s lid is open or badly sealed, then the kettle will take longer to boil the water. Sometimes, you can solve the problem by making sure that the lid is securely in place but if there is a design fault, then you might want to consider replacing the kettle if the longer boiling point is unacceptable to you.

A Quick Summary On Why Kettles Boil Longer Than They Should

  • When a kettle boils longer than normal, several things could be responsible.
  • The most common causes include open lids, cold water, too much water, limescale, and atmospheric pressure. 
  • Most of these causes can be solved at home.

About the Author Harry Thompson

Gaining a BSc Honours in building/ property maintenance at the University of Portsmouth Harry went into the field of renovating properties. Along the journey, he has developed a wide variety of home & garden DIY skills such as installing new kitchens and landscaping gardens.