Kilrock Big K Multi-Purpose Descaler - 400ml

Kilrock Big K Multi-Purpose Descaler - 400ml

Product code
Kilrock Big K Multi-Purpose Descaler - 400ml is rated 4.9 out of 5 by 94.
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2 for £8
In Stock

Delivery Options

Delivery to most of UK Mainland from £4.95

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Free Click & Collect

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  • Overview
  • Reviews (94)
  • Delivery
  • Returns

This Kilrock limescale remover is a brand leader that totally clears even heavily scaled appliances in just 5 minutes.

It removes hard water drip stains quickly and effectively from baths and taps and is ideal to use with metal or plastic kettles, shower heads, coffee makers, steam irons and toilets.

This is the original 5 dose multi-purpose descaler with a unique biodegradable, phosphate-free formula has been descaling kettles for over 70 years: nothing performs like it!

You'll get your home de-scaled in no time at all with this limescale remover by your side!

Features and Benefits

  • Descales in five minutes – This limescale remover can rid appliances from heavy limescale in just five short minutes.
  • Removes hard water drip stains – Great for use on baths, taps, metal or plastic kettles, shower heads and more. 
  • Phosphate-free – Phosphates are known to be bad for health and very damaging to the environment, so being phosphate-free is a great bonus for both you and the planet. 


  • Made in the UK
  • 400ml provides 5 doses
  • Phosphate-free

How To Use

  • Metal or plastic kettles: Half fill the kettle with water and bring to the boil
  • Stand kettle in a bowl in the sink in case of excess fizzing
  • Add 1 measure of Kilrock-K and leave for 5 mins or until the fizzing stops
  • Pour away contents, reboil kettle and pour away and rinse before reuse
  • Wash off any spillage
  • Shower heads: Mix one part Kilrock-K and 8 parts warm water in a bowl
  • Immerse head in solution until fizzing stops
  • Rinse head and bowl in cold water before reuse
  • Coffee makers: Refer to manufacturers handbook
  • Mix one part Kilrock-K and 8 parts warm water and carefully add to the appliance reservoir
  • Switch on and run as normal. Empty and repeat process twice with clean water
  • Steam irons: Mix one part Kilrock and 8 parts warm water in a jug
  • Warm iron and unplug
  • Pour solution into chamber to normal level
  • Place an upturned saucer in a plastic bowl and place the iron, soleplate down, on the saucer
  • Depress the steam button until all the solution is used. Repeat process with cold water
  • Wipe soleplate and iron ready to use
  • Toilet pans: Add 1 litre of hot tap water to the pan
  • Pour 2 measures of Kilrock-K into the pan
  • Leave until it stops fizzing. Brush and flush


  • Contains Formic Acid
Reviews (94)
Rated 5 out of 5 by from Great Product - does what it says On a visit to our daughter's in Didcot, & visited the Robert Dyas store (our own home area doesn't have one, but I think that they are wonderful shops). Found all we were looking for, & then at the counter I was recommended this product - & descaler was something else we were going to get elsewhere. Descaled our daughter's very badly scaled kettle - & it was clear in 5 minutes, as it said on the can. Brilliant product. Now home with no Robert Dyas within range, so the question now is whether I pay out for the delivery cost by buying it online.
Date published: 2019-06-25
Rated 5 out of 5 by from Twin pack Kilrock Big K Multi-Purpose Descaler If you live in a hard water area, I cannot recommend Kilrock highly enough as the best way of cleaning limescale from Kettles, Shower Screens, toilet bowls, sink areas. It works better than anything else. But do use gloves, as the waste product of Kilrock + Calcium in the hard water is acidic in nature and will burn bare skin (slowly, so you can wash it off quickly if you get it on bare skin)
Date published: 2019-02-27
Rated 5 out of 5 by from Incredible Product I have been searching for years to find a product that will descale our toilet, and now I've found it. I put it in my loo overnight and flushed and brushed the following morning. 95% of the limescale just fell away. I poured a little more on the stubborn area. I loo is lovely and clear now. Just give it a go and surprise yourself. I'm one very happy lady now.
Date published: 2017-03-03
Rated 5 out of 5 by from Kettle descaler I have used this product many times before as I live in a hard water area and its not pleasant when you get scum on top of your cup of tea and bits of scale at the bottom. This product works in minutes and is simple to use, just stand well back when adding it to the boiling water as the fumes are very pungent.
Date published: 2017-05-08
Rated 5 out of 5 by from Kilrock Descaler Was selling this as a trail size to customers and have to say this is the best descaler i have ever used. Its so good you can actually see your reflection at the bottom of kettle, Say goodbye to limescale forever, the kettle is now as good as new. Whats in it for you, you may ask. No i dont work for Kilrock and certainly dont get commision from Dyas as my customers have joked with me in the past. I am very passionate about providing a positive review when something really is better than it says on the tin.
Date published: 2018-03-11
Rated 5 out of 5 by from Quick and easy I have tried many different descalers for my kettle and this one seems to descale quickly. It takes away all of the limescale in one go where as other descalers sometimes require two applications. This descaler is not as cheap as some but definiatey does the job.
Date published: 2017-08-15
Rated 5 out of 5 by from The BEST EVER I bought this to descale my toilet. I had tried many things before (including Coke) and nothing had worked, then a friend recommended Kilrock K and it worked really fast. Since then, I've been recommending it to everyone I know! FANTASTIC PRODUCT
Date published: 2017-06-07
Rated 5 out of 5 by from Clean kettle! Brilliant de scaler... I use much less than recommend in just boiled water. I only leave in for a couple of minutes, rinse, boil again, rinse again then I have a scale free kettle for a couple of weeks. Bought on special deal so even better!
Date published: 2019-05-27
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Standard Products 

The table below outlines our different delivery charges which will be calculated on the basis of what you are ordering, where you are asking us to deliver to and what day you wish us to make a delivery. You can be confident that you will only pay one delivery charge per order regardless of how many items you order.

Delivery Charges

Standard Next Day Named Day Saturday
Mainland UK (ex Isle of Wight) £4.95 £5.95 £5.95 £7.95
Highlands & Scottish Isles £10.95 N/A N/A N/A
Northern Ireland & Isles £10.95 N/A N/A N/A

Standard delivery to most of UK Mainland is FREE on orders over £50 from Robert Dyas, and is only available on Standard products. To take advantage of this offer, simply enter promotion code FREEDEL50 at the checkout (cannot be used in conjunction with any other promotion code). This offer excludes products with bulky delivery charges, Robert Dyas gift vouchers, selected tools and DIY, hostess trolleys, food hampers and items for delivery to Northern Ireland, Scottish Highlands, Scottish Isles, Isle of Man, Isles of Scilly and Isle of Wight.

Scottish Highlands & Islands postcodes: AB, FK, HS, IV, KA, KW, PA, PH, ZE, LL58-LL78, IM, TR, BT, PO30-41

Typical delivery time windows: Monday-Friday: 08:00 - 19:00, Saturday: 08:00 - 18:00

For most orders, you will receive a text message update the evening before your delivery. You will receive a further text message on the morning of your delivery, providing you with a 2 hour delivery window.*

*Please make sure you enter a mobile number during checkout to receive text message updates.

Click & Collect

Robert Dyas offers a FREE Click and Collect service to Robert Dyas stores.

If you choose to have your order delivered to your local store, it is completely free and will be delivered within 5 working days (excluding Bank Holidays).

When your order arrives in your chosen store, we will e-mail you to advise that your order is ready for collection. Your order will be held in store for 7 days.

Standard Delivery

We aim to deliver items that are currently in stock within five (5) working days (excluding Bank Holidays) after the date the order is placed.

Unfortunately at this time we cannot take orders for delivery to British Forces Post Offices (BFPO), Freight Forwarders, international addresses or The Channel Islands (GY, JE).

The following areas are subject to extended lead times:

  • Scottish Highlands & Scottish Isles: +7 days
  • Isle of Man & Isles of Scilly: +2 days
  • Northern Ireland: +4 days
  • Isle of Wight: +5 days

Please note that during particularly busy periods, it may take a little longer to receive your delivery and our carrier may attempt to deliver to you on a Saturday.

Working days are defined as Monday-Friday 8am-7pm inclusive, excluding Saturday, Sunday and Public Holidays.

Next Day & Named Day Delivery

Our Next Day service to most of UK Mainland will be available for orders placed on the website from Monday to Friday before 3.00pm for a small additional charge (delivery on working days only). Orders placed after 3pm on a Friday will be delivered Tuesday.

You can also select a convenient day to receive your delivery by choosing a named day delivery (delivery on working days only).

Working days are Monday-Friday 8am-7pm inclusive, excluding Saturday, Sunday and Public Holidays.

Saturday Delivery

Orders placed before 3.00pm on a Friday (excluding Bank Holidays), can be delivered on a Saturday for an additional charge.



In the UK you have a legal right, under the Consumer Contracts Regulations June 2014, to cancel your order within fourteen (14) days following your receipt of the goods. Refunds for orders cancelled under the provisions of the Consumer Contracts Regulations will be processed in accordance with your legal rights.

You may not cancel orders for the following types of products:

  • Electrical/Technical products which have been unsealed
  • Customised or bespoke Products
  • Anything of a nature that for hygiene or associated health and safety - this includes the Outdoor Spas, Mattresses and Divan Sets
  • Fresh food

Under the Consumer Contracts Regulations June 2014 you have a duty to take reasonable care of Products whilst they are in your possession. You will receive a full refund of the purchase price of the Products.

This is not intended to be a full statement of your rights under the Consumer Contracts Regulations. Full details of your rights are available from your Local Authority’s Trading Standards Office.

How To Return A Product

If you wish to return your item to Robert Dyas, you can do so by one of the following methods:

1. Request a Collection via Robert Dyas Customer Services

Contact our Customer Services team on 0333 103 6677 (Monday- Friday 08:00 - 20:00, Saturday-Sunday 09:00 - 17:00 - call charges may vary by network) or via email to: [email protected] who will be able to arrange a collection for your item. Please ensure that you provide your order number when contacting customer services.

If you are returning the item under your 14 day right to cancel, then a collection charge will be applied:

  • Products < 20kg: £7.50
  • Products > 20kg: £30

If you are not at home when we try to collect we reserve the right to deduct from your refund or charge your credit card the direct costs to us of the failed return in accordance with the Consumer Protection (Distance Selling) Regulations 2000.

2. Post back the item to the Robert Dyas Warehouse

Click here to download a returns form or use the form on your delivery and returns note, enclosed with your goods. This method of return will be at your own cost. We also recommend obtaining proof of postage in case the item is not received by our warehouse.  

Please return items to:

Returns Department
Robert Dyas Distribution Centre
Swallow dale Lane
Hemel Hempstead

3. Visit Your Local Robert Dyas Store

Whether you bought the product in store, online or over the phone, most of our products can be returned to a Robert Dyas stores. Please bring your order confirmation as proof of purchase. Please do not attempt to return large or heavy products, including large kitchen appliances, outdoor furniture, indoor furniture etc to your local store. If in doubt of whether you should return a product to your local store, please contact customer services first.