Hard Water & Descaling: Kettles, Irons and Shower Heads

Hard Water & Descaling: Kettles, Irons and Shower Heads

If your kettle has a white crust inside, your iron spits brown water on a white shirt, or your shower head sprays sideways, you do not have faulty appliances. You have hard water — and in much of Kenya, especially where supply comes from a borehole, that is the default. Descaling is a maintenance habit, not a repair.

How to tell if your water is hard

You do not need a test kit. Hard water announces itself:

• White or grey crust inside the kettle, thickest at the element or base.
• Soap that will not lather and leaves a film on your skin rather than rinsing clean.
• White spots dried onto glasses and cutlery even after a proper wash.
• A shower head that sprays unevenly or in the wrong direction — mineral blocking individual holes.
• Brown or white flecks from a steam iron.
• Chalky rings in the toilet and around taps that come back quickly after cleaning.

Borehole supply is generally harder than piped municipal water, which is why two houses on the same street can have very different experiences — one on mains, one on a borehole.

What scale actually does

Limescale is a mineral deposit, and it is a good insulator. That is the problem.

• A scaled kettle element has to push heat through a mineral layer, so it takes longer and uses more power for the same boil.
• A scaled shower heater works harder and eventually fails at the element.
• A scaled iron blocks its steam holes and then deposits the loosened residue onto fabric.
• A scaled coffee maker brews slower and cooler, which changes the taste before you notice the cause.
• Scaled taps and shower heads restrict flow and spray erratically.

Scale is not cosmetic. It shortens the life of every heating element in your house.

Descaling schedule by appliance

Appliance	Hard water area	Soft water area	Method
Electric kettle	Every 2–4 weeks	Every 2–3 months	Vinegar or citric acid solution, boil, soak, rinse
Steam iron	Monthly	Every 2–3 months	Self-clean function; use distilled water going forward
Coffee maker	Monthly	Every 2–3 months	Run a descaling cycle, then two water-only cycles
Shower head	Every 2–3 months	Twice a year	Unscrew and soak overnight
Water dispenser	Every 2–3 months	Twice a year	Descale and sanitise the tank
Washing machine	Monthly maintenance wash	Every 2 months	Empty hot cycle with descaler
Pressure cooker	When you see film	Occasionally	Vinegar soak; check the valve is clear

How to descale a kettle, properly

1. Fill to roughly half with equal parts water and white vinegar. Alternatively use a spoon of citric acid in water.
2. Bring it to the boil, then switch off.
3. Leave it to stand for an hour. This is the step people skip, and it is the step that does the work — boiling alone loosens very little.
4. Pour out, and wipe away softened deposit with a cloth.
5. Boil two full loads of clean water and discard both. Do not skip this or your tea will taste of vinegar.

Never scrape a kettle element with anything metal. Scratching the element gives scale more surface to cling to, and it will re-form faster than before.

The iron, which causes the most visible damage

A scaled iron ruins clothes, which makes it the one worth staying ahead of.

• Use distilled or deionised water if your area is hard. It is the single most effective preventative step and costs very little.
• Never use borehole water in a steam iron. It scales fastest and stains worst.
• Empty the tank after every session. Water left standing deposits minerals as it evaporates.
• Run the self-clean function monthly over a sink, not over a garment.
• Test on a cloth first after any descale, before it touches a white shirt.

Prevention beats descaling

• Empty the kettle after use rather than leaving water standing. Standing water is what deposits scale.
• Boil only what you need — less water through the kettle means less mineral left behind.
• Filter water for appliances if your supply is very hard. A filter jug for kettle and coffee-maker water is cheaper than replacing either.
• Wipe taps and shower screens dry after use. Scale forms as water evaporates, so removing the water removes the deposit.
• Use a rinse aid in the dishwasher, or dry glasses by hand, to stop spotting.
• Consider a whole-house softener if you are on a borehole and replacing elements regularly — at that point it is a cost decision, not a comfort one.

What not to do

1. Do not use bleach to descale. It does not dissolve mineral and it damages some surfaces.
2. Do not use steel wool on stainless steel. It leaves scratches that trap deposit and can rust.
3. Do not descale a hot appliance. Let it cool first.
4. Do not put vinegar in an appliance whose manual forbids it — some coffee makers and steam appliances specify their own descaler for good reason.
5. Do not ignore a slowing kettle. By the time boiling is noticeably slower, the element is already working through a thick layer.

Frequently asked questions

Is water in Kenya hard?

In many areas yes, particularly where supply comes from a borehole. Piped municipal water is generally softer, so two neighbours can have quite different experiences.

How often should I descale my kettle?

Every two to four weeks in a hard water area, and every two to three months where water is softer.

Can I use vinegar to descale a kettle?

Yes — equal parts water and white vinegar, boiled and then left to stand for an hour. Afterwards boil and discard two full loads of clean water.

Why does my iron leave brown marks on clothes?

Mineral deposit inside the tank being pushed out with the steam. Run the self-clean function and switch to distilled water.

Does limescale increase electricity use?

Yes. Scale insulates the heating element, so the appliance runs longer to reach the same temperature.

What water should I use in a steam iron?

Distilled or deionised water in hard water areas. Never borehole water.

Can I scrape scale off a kettle element?

No. Scratching the element gives scale more surface to grip and it returns faster. Dissolve it instead.

Look after your appliances

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