6 Effects of Hard Water On Espresso Machines & Coffee Makers

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If you have a drip coffee maker, an espresso machine, or a French press, using hard water in your machine is likely to have several unwanted side effects.

Here, we’ve shared the common effects of hard water on coffee makers and espresso machines.

📌 Key Takeaways:

  • Water with a high mineral content is known as hard water.
  • Hard water reduces your coffee machine’s heating efficiency, clogs the pipes and lines in the machine, increases maintenance and repair work, shortens the machine’s lifespan, and affects how coffee tastes.
  • You can avoid the effects of hard water on coffee machines by installing a water softener in your home.

🚱 What Is Hard Water?

Hard water is any water source that contains a lot of dissolved magnesium and calcium minerals. The more minerals the water contains, the harder it is.

Hardness minerals enter a water source as it flows over or through mineral-rich rocks and soils. Surface water and groundwater supplies in most parts of the world contain hardness minerals.

The majority of tap water supplies in the US are naturally hard. Hard water is safe to drink, but it damages the appliances and fixtures used all around your home, including your coffee maker.

Hard water buildup on faucet

📋 6 Common Effects Of Hard Water On Coffee Machines

Let’s review the 5 most common effects of hard water on an espresso maker or coffee machine.

1) Reduced Heating Efficiency

A coffee maker is unable to heat water efficiently if hard water is used in the machine.

Over time, a buildup of hardness minerals in the heating tank form a layer of insulation, so the machine must work longer to heat the water inside to the desired temperature.

This reduced heating efficiency means that more energy is required whenever you switch on your coffee maker, and the machine’s electric parts will wear more quickly.

2) Increased Wait Time

If you’re the sort of person who can’t function in the morning without your cup of coffee, here’s some news you probably don’t want to hear: using hard water in your coffee machine will slow down the coffee production process, so you have to wait longer for your cup of joe.

This additional production time is a result of the machine’s reduced heating efficiency, caused by hard minerals accumulating in the water tank.

As limescale accumulates, you’ll notice that your wait time for a fresh cup of coffee gradually increases, as the machine takes longer and longer to heat the water to the desired temperature for coffee making.

Limescale in coffee maker water tank

3) Clogged Lines

Limescale doesn’t only clog your coffee machine’s heating tank – it also builds up in the pipes and lines inside of the system.

This buildup will reduce the flow of liquid through the system, which will also slow down the coffee production process.

Larger chunks of limescale may break off from the heating tank and clog the pipes leading to the dispenser spout, resulting in a system malfunction.

If this happens, you’ll need to take the machine apart and flush the clogged pipe to get the machine usable again.

4) Increased Maintenance & Repairs

Brewing coffee with hard water means you’ll have to add a new task to your cleaning process: descaling.

Descaling removes the mineral deposits from inside the machine. The manufacturer should advise on how often to descale your coffee maker in the user manual. Newer machines have a display screen or a warning light that alerts you when the machine needs to be descaled.

There are different methods of descaling, and you could use white distilled vinegar as a natural descaler or purchase a commercial descaling liquid. The process involves partially disassembling the machine and running it through a complete cycle using the descaling solution, then flushing the system with clean water.

Even self-cleaning coffee makers may require additional descaling with a special solution to prevent a buildup of mineral deposits inside the machine.

Due to the reasons outlined above, you may also have to repair your coffee maker or espresso machine more regularly as a result of hard water exposure – even if you use a descaling liquid in the machine as recommended in the user manual.

Cleaning a coffee maker with limescale

5) Shortened Lifespan

It’s hardly surprising that coffee and espresso machines don’t typically last as long as anticipated when they’re used with hard water.

The mineral buildup inside a coffee machine prevents it from operating as intended, and the electrical components have to work harder to achieve the same (if not a slightly less favorable) end result.

That puts the machine at a higher risk of burnout and decreased performance due to wear-and-tear at a faster rate.

You may find that you become quickly impatient with your coffee maker’s reduced efficiency or poor performance, and end up buying a new machine after just a few years of use.

The problem is that all other coffee makers will meet the same early end if you continue to use hard water in the brewing process.

6) Altered Coffee Taste

Although not a direct effect on the machine itself, hard water can affect the taste of your coffee.

If you’re something of a coffee snob and will only drink the most delicious coffee or great-tasting espresso, you won’t be pleased to hear that high levels of hardness minerals can leave your coffee tasting bitter and dull.

Magnesium tends to bring out sharper flavors in your coffee beans, while calcium gives the coffee bitter notes and a chalky feel.

While low levels of minerals can be pleasant in a cup of coffee, water with a high mineral content may result in an unpleasant-tasting beverage.

Woman drinking bitter-tasting coffee in a cup

📖 How To Avoid Hard Water Effects On Coffee Makers And Espresso Machines

Here are our top recommended ways to avoid the effects of hard water in your coffee maker.

Install A Water Softener

Want to avoid having to descale your coffee maker regularly?

It’s much easier to keep your coffee maker clean, and you can enjoy better-tasting coffee from a machine that’s more efficient and lasts longer, if you exclusively use soft water for making coffee.

The most effective way to turn your home’s hard tap water into soft water is with a water softener.

A water softener system is a point of entry unit that softens water upstream of your water heater, so all the hot and cold water in your home is free from all the minerals responsible for limescale formation.

That means the water from your faucet that you use in your coffee machine will be soft and free from minerals that could cause scale inside the system and affect your coffee’s taste.

What does that mean? Better coffee for you, longer-lasting appliances, and reduced energy costs to run your coffee maker.

Installing water softener home prevents limescale buildup

Use RO or Distilled Water

If you don’t want to spend a lot of money upfront, our alternative recommendation to avoid the effects of hard water on your coffee maker is to buy distilled or reverse osmosis bottled water for making coffee.

Reverse osmosis and distilled water are a level up from filtered water – these water types have been purified to remove all their impurities, including all minerals and salts.

Like soft water, distilled and RO water are unable to form scale inside your coffee maker. These water types are also free from any other contaminants that could damage your machine, like chlorine, sediment, and iron. So if you really care about the longevity of your coffee maker, you know what to do.

However, the reason why we don’t recommend distilled or RO water before soft water is that these water types have a flat taste and a lack of flavor that will affect the taste of your coffee. Softened water shouldn’t have this issue because water softening doesn’t have a huge impact on pH or TDS.

Getting filtered water from an RO system

📑 Final Word

Hard water has numerous effects on coffee makers, and even the best coffee maker with a self-cleaning feature isn’t protected against scale formation.

If you want to enjoy a better-performing, longer-lasting coffee machine that gives you better-tasting cups of coffee, we recommend installing a water softener (see our top picks here) and using only soft water in your machine.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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