Limescale build-up is a natural result of heating water, but over time it can reduce performance, affect taste, and shorten the lifespan of your appliances. Regular descaling keeps your appliances working efficiently and reliably.
This guide explains what descaling is, the best descaling solutions, and how to descale kettles, instant hot water dispensers, and irons step by step.
What Is Descaling?
Descaling is the process of removing mineral build-up (limescale) from appliances that heat water.
Limescale forms when water containing minerals like calcium and magnesium is heated. Over time, this build-up can:
- Reduce heating efficiency
- Affect water flow and performance
- Leave residue or odours
What Is the Best Descaling Solution?
The best descaling solution depends on your preference. All of the following are effective:
Commercial Descaler (Fastest Option)
- Designed specifically for appliances
- Quick and highly effective
- Follow product instructions carefully
Citric Acid (Best All-Round Natural Option)
- Mix 1 tablespoon with 1 cup of hot water
- Effective, low odour, and widely recommended
Vinegar Solution (Strong Household Option)
- Use ½ cup white vinegar with water + 1 tablespoon baking soda
- Powerful, but may leave a temporary smell
Lemon (Mild Natural Option)
- Add juice from half a lemon to water
- Suitable for light descaling
Before you begin: Remove loose scale and gently clean surfaces with a soft brush or sponge.
How to Descale a Kettle
To descale a kettle: boil a descaling solution, let it sit, then rinse thoroughly.
Steps:
- Fill the kettle with your chosen descaling solution
- Bring to the boil (avoid steam where possible)
- Leave to sit for 20–60 minutes
- Empty and rinse thoroughly
- Boil fresh water and discard before use
Regular descaling helps maintain fast boiling times and clean-tasting water.
How to Descale an Instant Hot Water Dispenser
To descale an instant hot water dispenser: run descaling solution through the system, then flush with clean water.
Manual Descaling:
- Fill the reservoir with your chosen solution
- Set to 100°C and continuous flow
- Dispense all liquid into a suitable jug
- Discard the solution
- Rinse and refill with clean water
- Flush at least 1 litre of fresh water through the system
- Use the dedicated descaling function as outlined in the manual
- The appliance will empty the tank automatically
- Do not refill the tank during the cycle
Regular descaling ensures consistent water flow and temperature performance.
How to Descale an Iron
To descale an iron: run a vinegar or self-clean cycle through the steam system, then rinse thoroughly.
Internal Descaling:
- Mix ½ cup white vinegar with ½ cup distilled water
- Fill the tank and heat to a high setting
- Activate steam over a sink until empty
- Refill with distilled water and repeat to rinse
- Clean steam vents with a cotton swab if required
Using the Self-Clean Function:
- Fill the tank and heat to maximum
- Unplug and hold over a sink
- Activate self-clean and gently shake
- Allow scale and water to flush out
Cleaning the Soleplate:
- Apply a paste of baking soda and water
- Wipe clean with a damp cloth
How to Prevent Limescale Build-Up in your Iron
- Use distilled or demineralised water where possible
- Empty water tanks after use
- Allow appliances to dry between uses
- For irons, consider using water from a Westinghouse Condenser Dryer
Descaling FAQs
Can you use vinegar to descale appliances?
Yes. Vinegar is effective for most appliances, though rinsing thoroughly is important to remove odour.
What is the safest natural descaler?
Citric acid is widely considered the best natural option due to its effectiveness and low odour.
How Often Should You Descale Appliances?
Descale appliances every 1–3 months, depending on usage and water hardness.
- Frequent use or hard water = more regular descaling
- Light use = less frequent maintenance
Reference the handy table at the top of this page for tips on this.
Why is descaling important?
Descaling improves efficiency, maintains performance, and helps extend the life of your appliance.
Regular descaling is a simple step that keeps your appliances performing at their best—delivering reliable results every day.