We have just brought a Buffalo K711 4.25L Electric Airpot that is great for my wife as she is disabled and can find a kettle hard to pour.


I was expecting it to be well insulated, however its sides feels very warm while it is running, so making me think it is wasting lots of power. We don’t need to fill it up completely, I am planning on putting 1l of water in it and topping it up a few times a day with 0.5l at a time, so reducing the amount of water that is heated.

I need to decide quickly if I am going to send it back, and don’t have an plug in energy meter.

(In the UK there are very few Electric Airpots on the market and the counter top “instant” water dispensers are very slow at filling a teapot. The under counter systems are very expensive.)

  • You could possibly make a kettle-cosy for it, but that would probably void the warranty. Also, your local council or polytech may have a meter you can borrow or use, especially since the device you want to test is portable. And I fear that your question is too specific for this site.
    – Móż
    Dec 10, 2013 at 21:03
  • 1
    If you edited the question to be "my wife is disabled and would like a continuous source of boiling water for hot drinks" or something, I could make these comments an answer and other people could chime in. That way you might get something more imaginative than my "duct tape and knitting" solution.
    – Móż
    Dec 10, 2013 at 21:46
  • 1
    If you'd like to ask a question about that or edit this question that would be good. I'm going to flag the question as not useful since you've returned the item you're asking about.
    – Móż
    Dec 10, 2013 at 23:52
  • 3
    @Ӎσᶎ - I wouldn't add extra insulation to one of these devices since the wiring and electronics tucked into the unit may rely on heat escaping to stay cool -- if a lot of heat escapes from the unit, anything wrapped under the insulation may rise to the temperature of the water.
    – Johnny
    Dec 11, 2013 at 1:36
  • 2
    I'll wait for more community input before taking any action, but at the moment, this question looks like it could use some work if it's to remain here: it could be more general, and thus be more useful to a wider range of readers. I appreciate that the OPs immediate question has changed, now that the specific item isgoing to be returned, but the general question behind it, of efficient heating of potable water for someone with impaired grip or lifting, is a good one.
    – 410 gone
    Dec 11, 2013 at 1:48

2 Answers 2


Reducing the amount of water being heated will also reduce the mass of water that is storing heat within the unit, and possible make it even less efficient. You might actually get better results keeping it full.

The best way to answer your question is with one of those plugin energy meters, but you say you don't have one. Does anyone you know, or perhaps your utility company, have a meter you could borrow for a day? Otherwise, the best any of us can do is guess how much the kettle is using when in standby mode.

  • I agree, using an energy meter may be the simplest solution. Here in The Netherlands many hardware shops sell energy meters for 10-20 euros (about 13.8-27.6 US dollars). One particular device which costs 10 euros has even been tested by a consumers union to be almost as accurate as a professional power meter of 250 euros.
    – THelper
    Dec 12, 2013 at 8:20
  • I do not understand the idea why smaller amount of material holding heat makes electrical resistance heating and heat keeping less effective. --- Normally it should be the contrary -- smaller amount of heat (smaller amount of heated material) -> less heat to dissipate. -- It could be more efficient if you need to store the energy (in the form of heat) for example if the energy is cheaper (either economically or ecologically) at certain time periods. Dec 13, 2013 at 9:10
  • Mass definitely affects heat keeping. I'm not sure what effect it has on electrical resistance.
    – TeresaMcgH
    Dec 13, 2013 at 15:31

I found a similar product that uses 700 watts while heating but you can select the temp setting if want water . I presume that the heater is just on/off depending on the temp of the water. I would select temperature to be at 140 degrees F, which would save even more or crank only to HI when wanting a cup of 205 degree water.

Product DESCRIPTION: Always have hot water ready at your fingertips with the new Sunpentown Hot Water Dispenser. It features one-touch dispensing, auto re-boil and micro-computerized dry-boil protection. Its multi-temperature function allows you to select and maintain one of three temperature settings. It has a stainless steel body with black trimmings for a sophisticated look. It is ideal for tea lovers or anyone who needs hot water handy. Simply add drinking water and the unit automatically starts to heat the water to the boiling point.

Sunpentown 3.2 Liter Hot Water Dispenser with Multi-Temp Function, Stainless Steel: 1-touch auto dispense 3 temperature selection (208 degrees F, 185 degrees F, 140 degrees F) Stainless steel inner pot Safety lock feature Micro-computerized dry-boil function 120V/60 Hz/700W Dimensions: 10.24"W x 10.24"D x 13"H Model# SP-3203

  • 3
    The 700W consumption power indicates how fast can the device heat the water up. It does not say anything about the actual power consumption of keeping the water hot. Dec 17, 2013 at 22:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.