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Instant boiling water taps...(mis)information alert!

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Having clear transparent information on the running costs of energy hungry products is essential.

The common perception is that instant boiling hot water taps are a cheaper alternative to using an ordinary kettle.

Yet, as you can see from my other article this is only the case if you use significant amounts of boiling water.

In this article I am specifically talking about the type of instant boiling water taps that keep a quantity of water permanently hot and available.

I recently gathered a set of cost information from marketing literature for these products, and found that it is frequently vague, selectively chosen, or quoted without assumptions.

Most worrying, I have recently found many examples of wholly, materially and significantly incorrect marketing information that I am warning about in this article.

There is therefore a risk that consumers are not being informed correctly and are not being given the information they actually need to make sensible purchasing decisions.

I believe that the scale of these errors could significantly influence the decisions of those buying these products by indicating that they use very little or less energy than they do in reality.

I lay out the evidence for the scale and nature of these errors in this article.

I am flagging to anyone interested in buying one of these products that they need to be very wary of the information they are presented with by product manufacturers.


The conclusions from my analysis and evidence search

I researched the running costs of instant boiling water taps from information provided online and by email from four different distributors or manufacturers, and information available at the Grand Designs Live event in October at the NEC.

I lay out the evidence of incorrect information below, together with a mark-up of the true facts from my analysis of these products.

  • I found no cost figures in any marketing literature I looked at that were correct. Gulp! The vast majority were substantially or wildly incorrect. It also looks like many of the figures used are based on energy tariffs that are very out of date. and a number that can only be based on tariffs from as far back as 2010.

  • I found no examples of clear understandable explanations of comparative costs with a kettle.

  • While instant boiling water taps are generally going to be purchased for their convenience, I think consumers also believe they are buying them in order to save significant amounts of money and use that belief as part of their justification for the investment.

  • A common frequent claim about these products is that they save you water with one web site claiming it can save 100 litres/year. This can only be on the assumption that you overfill a kettle and then you pour away hot water that you do not use. I don't know why anyone would do that, and I know of no-one who does, so that rationality of that claim is a mystery to me.


The evidence

To keep this article concise I am assuming that you read the other article before you read this one.


Case by case evidence

Fohen - manufacturer

The webpage screenshot here is the only information I can find on their web site of costs (as of 17th Oct 2022).

As you can see, every number is incorrect. The energy tariff I have used is 27p/kWh (the standard tariff from October 2023)

One of the figures is less than a tenth of the correct figure based on my analysis. - product distributor

The photograph here was displayed at their stand at the Grand Designs Live event at the NEC in October 2022.

The kettle boiling cost figures are to be frank the funniest ones as it has NEVER been this expensive to boil a kettle. Even if a home is on an Economy 7 daytime tariff the cost to boil a kettle is less than this.

Looking at their web site I found the following information and errors, which consistently and significantly understate the costs of using an instant boiling water tap.

It also forgets to take all the costs into account in the final sentence, which at best is a flawed pseudo comparison with kettle costs.


Quooker - manufacturer

Quooker have no information of costs on their web site (as of 17th October).

Their sales representative at the Grand Designs Live show in Oct 2022 told me that the cost per litre of using one of their taps was 1p and the daily running costs 3p. These figures match those on one of their product distributors in the screen-shot below.

I have challenged Quooker subsequently who acknowledge that current tariff information may not have been used.

Based on that analysis, I looked back at historical UK energy tariffs to work out when their cost claims WOULD have been valid. The answer as you can see in the chart....was 2010.

In the absence of any other information to the contrary, all I can conclude is that Quooker has been using outdated figures for around 12 years.


Intu - manufacturer

This screen shot is from the Intu summer 2022 catalogue, downloaded from their website 10th Oct 2022. The energy cost I assume in the yellow bubble is the Oct 2023 27p/kWh tariff.

I have not looked at other manufacturers.


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Mark Thompson

Get Energy Savvy - simple practical home energy efficiency information

341 views2 comments


J Eric Lindsay
J Eric Lindsay
Dec 23, 2022

One mugs worth of water - 300 cc

after boiling in kettle is reduced to 290cc with 10cc lost as water vapour ( 3.3% )

Mark Thompson
Mark Thompson
Dec 23, 2022
Replying to

That sounds about right 👍

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