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Do you leave your boiling water tap on at nigh?


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First night at the new house. So far, so good… I think.

 One thing I’ve noticed is every 15 minutes or so the boiling water tap makes a bit of noise for about 2 minutes. It’s not very loud, just sounds like a very quiet kettle, and I’m sure I can easily soundproof the cupboard the 2.1L tank is in. But it did make me think about the energy it is using, reboiling  the water to 98C. Do you turn yours off at night and then back on again in the morning? Or does that defeat the purpose?

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We leave ours on.
 

Did turn it off a couple of times overnight a while back but then it took a while (sub 1 minute iirc) to get back up to temperature when we turned it back on, so gave that a miss. 

Pretty sure ours isn’t reheating every 15 mins but it’s out of earshot so don’t really know for certain but looking at our energy consumption through the wee small hours it looks like it does nothing - if it does do anything, it’s insignificant.  It does take 4-5 seconds to produce boiling water first thing in the morning though whereas through the the day when it’s being used fairly regularly it’s probably more like 1-2 seconds. 

 

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Congratulations on moving in, and bigger congratulations that this is the biggest issue on your mind!! It must have gone well 

 

Our is controlled by the home automation so it only turns on when people are in the house and moving around. I also give it a burst at 4.20 am (last blast on cheap rate electricity) and whenever the solar is above 5kW or something.

It is nice opening the door when coming home to hear the click of the kettle going on and the whir of the water mains stopcock open.

 

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19 minutes ago, joth said:

Congratulations on moving in, and bigger congratulations that this is the biggest issue on your mind!! It must have gone well 

Thanks. There is still a ton of snagging to deal with, but hopefully this will get sorted soon. The most annoying is that we have a light in our bedroom which we can’t turn off. It dims down to minimum, but not off completely. Second most annoying is a high pitched sound in my daughter’s bedroom. Not loud enough to bother her, but my wife did notice it and now I have too. I think it is coming from the mains wired smoke alarm in her room. Will investigate further tomorrow.

Third most annoying is that the builder forgot to put sealant in a couple of places.

 
The rain for focusing on the hot water tap is that it’s the only one I can do anything about!

 

19 minutes ago, joth said:

 

Our is controlled by the home automation so it only turns on when people are in the house and moving around. I also give it a burst at 4.20 am (last blast on cheap rate electricity) and whenever the solar is above 5kW or something.

It is nice opening the door when coming home to hear the click of the kettle going on and the whir of the water mains stopcock open.

 

That sounds very smart, but how did you configure that? Even if I put a smart timer socket on mine, and linked it to some sensors, wouldn’t I need to be physically by the tank to press the “on” button?  

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Our Quooker has been on continuously for the last three years 

Hope I wasn’t meant to turn it off each evening 😂

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8 hours ago, Adsibob said:

Even if I put a smart timer socket on mine, and linked it to some sensors, wouldn’t I need to be physically by the tank to press the “on” button?

Our one (Quooker Combi) doesn't have an on button. I just power it on at the mains and it's ready to deliver. (Obv not 100ºC if it's been off a while).

 

2 hours ago, nod said:

Hope I wasn’t meant to turn it off each evening 😂

 

My only motivation was energy/money saving, and it was very easy to do with the sensors etc already in place.

The biggest saving would be when away on holiday, except there's someone in at least once a day to feed the cats so it still has a daily boil regardless. ---- I could easy program the automation to remain off during holiday periods or ignore the cat sitter's keyfob code for this purpose, except it's a combi tank so provides the kitchen hot tap too - or they might what a cuppa. I'm sure the legionnaire police also approve 

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It would make no material difference to turn it off at night.

 

I would also be concerned that constantly turning it off and on would make it more likely to break.

 

It will lose a certain amount of energy over 24 hours. Whether you replace this all in one burst or in small increments over the day will make no difference. The only slight difference would be that you lose  less energy when the differential between the outside temperature and the water temperature is smaller, but in this case the water would barely cool down and that would be negligible.

 

The same principle applies to central heating in a well insulated house (in a badly insulated house the temperature could get down close to the outside temperature and the it would stop losing energy)

 

I am a little concerned if it needs to heat for 2 minutes every 15, that does suggest that it is not well insulated. We have a Quooker and you cannot hear it running, you can see the red light come on and maybe hear a click if it is quiet when that happens, but I don't think  it comes on that often. I would check your smart meter when it comes on to see how much energy it uses when it runs. If it runs 8 minutes an hour, that is over 3 hours a day. If it had a 1kW element that would cost almost £1 a day. Hopefully it has a really small element. Quooker quote 10W/hour heat loss, so around 0.24kWh a day or 7p. There should probably be a spec somewhere for standing losses.

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1 hour ago, AliG said:

It would make no material difference to turn it off at night.

What would the temperature of the water be in the morning if you turned it off overnight?  Room temperature?

Surely it must be wasting energy to have it top up the heat overnight.

 

I know nothing about Quookers and I can see the advantages of leaving it on (especially if that is how the manufacturers expect them to be used) but I can't see how you get round the point that it must be using more energy than needed if left on overnight.

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3 hours ago, AliG said:

It would make no material difference to turn it off at night.

It depends what material you are talking about. In terms of kWh I agree turning it off overnight has little difference, but as I say I do it to shift time of use to lower cost (both financial and CO2) times of day which does have a (small) material difference

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2 hours ago, jfb said:

Surely it must be wasting energy to have it top up the heat overnight.

 

The amount of energy you need to add is driven by the heat loss. It doesn't matter if you keep topping to up or do it all at once, the heat loss that has to be replaced is the same.

 

1 hour ago, joth said:

It depends what material you are talking about. In terms of kWh I agree turning it off overnight has little difference, but as I say I do it to shift time of use to lower cost (both financial and CO2) times of day which does have a (small) material difference

 

Yes. If you had different electricity prices at different times of the day then that would make a difference.

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20 minutes ago, AliG said:

 

The amount of energy you need to add is driven by the heat loss. It doesn't matter if you keep topping to up or do it all at once, the heat loss that has to be replaced is the same.

 

 

Surely that is not strictly accurate. The rate of heat loss when the differential between the tap's tank is at 98 degrees and the surrounding room temp is 20 degrees will be greater than when the tank has cooled to say 75 degrees. 

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I already explained that originally!

 

It’s not going to cool down enough for this to make a material difference but I mentioned it in case someone brought it up.

 

If it did cool down that much then it would cost a fortune to run and I’d be much more worried about that.

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18 minutes ago, AliG said:

I already explained that originally!

 

It’s not going to cool down enough for this to make a material difference but I mentioned it in case someone brought it up.

 

If it did cool down that much then it would cost a fortune to run and I’d be much more worried about that.

Sorry, missed that.

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1 hour ago, AliG said:

It’s not going to cool down enough for this to make a material difference but I mentioned it in case someone brought it up.

Does anyone know how well insulated they are? I mean if it was turned off how long before it reaches room temperature?

 

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16 hours ago, Adsibob said:

First night at the new house. So far, so good… I think.

 One thing I’ve noticed is every 15 minutes or so the boiling water tap makes a bit of noise for about 2 minutes. It’s not very loud, just sounds like a very quiet kettle, and I’m sure I can easily soundproof the cupboard the 2.1L tank is in. But it did make me think about the energy it is using, reboiling  the water to 98C. Do you turn yours off at night and then back on again in the morning? Or does that defeat the purpose?

 Congrats on moving in, we're in just over a week and I still jump and investigate at every noise, a dripping shower head had me convinced there was massive leak. Our taps makes a slight noise every 3 or 4 hours, a bit more if we've been using it. I think they are very well insulated, better be anyway.

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10 minutes ago, jfb said:

Does anyone know how well insulated they are? I mean if it was turned off how long before it reaches room temperature?

 

A quooker tank is about 10W heatloss at 100°C

 

I think very approximately this means the 7L version looses about 1°C per hour (when near boiling)

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i would guess it is this kind of boiler unit as it is 2.1litres in size and heats to 98C.

 

https://www.pronteau.co.uk/downloads/installation/proboil-2x-user-and-installation-guide.pdf

 

The manual is not exactly clear, but mentions 0.025kW heat loss at 98C. It doesn't say per what period, but I would guess per hour.

 

It also says that the maximum energy use is 1.5kW and it takes 9 minutes to heat the tank from 20 to 98C. It also says it takes 11 minutes to recover from 1l use and 7 minutes from 2l use which makes no sense at all.

 

The 9 minute heat up time is consistent with a 1.5kW heating element and 2.1l of water.

 

Anyway assuming 0.025kW heat loss then it would use 0.6kWh of energy per day or approx 18p. This suggests that it loses almost 10C per hour so I could see why it comes on quite often to reheat. However the element should only be running for approx 1 minute an hour. It may be that once it has been on the sound continues for a while, worth checking that's it is not running for as long as the sound can be heard.

 

To save money by turning it off it would have to get down to a point where the heat loss slowed considerably. The trouble is that the heat loss slows as it gets cooler and I don't know how to calculate the time it would take to  cool all the way down. The least it could be would be 8 hours, but it would be somewhat less as it would slow as it cools down.

 

There is an argument to turn it off when you go on holiday, saving just over £1 a week, but not to turn it off overnight.

 

 

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21 minutes ago, AliG said:

The manual is not exactly clear, but mentions 0.025kW heat loss at 98C. It doesn't say per what period, but I would guess per hour.

That means it is losing heat like having a 25w heating element under your sink.

 

So it will consume (thanks to that heat loss) 25wh in an hour and 600wh or 0.6kWh in a 24 hour period, just to make up the heat that it has lost.

 

so at present electricity prices it will be costing about 15p per day just to keep the water inside it hot and ready for use.

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Each time you boil 1l of water it uses around 0.1kWh so this is using the equivalent of 6 boils per day to keep the water hot, whereas a Quooker is using the equivalent of 2.5 boils/day. Assuming an average boil is around 1l.

 

We have a Quooker, but I am under no illusions that it is simply a very expensive and convenient kettle. I would note that almost everyone I know who has one loves it. If something does the intended job and you find it useful then the expense is less of an issue.

 

They try to make an argument that it saves money over a kettle as people tend to boil too much water. If you boil the kettle 10 times a day this would be true of a Quooker. This less well insulated device would probably need you to be boiling the kettle 13-14 times a day to save anything in terms of running costs. We certainly would never have boiled the kettle more than 10 times a day.

 

The reality is that no one should be buying these for running cost savings. You might save 10p a day in electricity, but only if you drink a lot of tea/coffee, but they cost the best part of £500-1500 to buy and install which more than offsets this. For most people they also actually cost a bit more to run than a kettle.

 

 

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4 minutes ago, AliG said:

Each time you boil 1l of water it uses around 0.1kWh so this is using the equivalent of 6 boils per day to keep the water hot, whereas a Quooker is using the equivalent of 2.5 boils/day. Assuming an average boil is around 1l.

 

We have a Quooker, but I am under no illusions that it is simply a very expensive and convenient kettle. I would note that almost everyone I know who has one loves it. If something does the intended job and you find it useful then the expense is less of an issue.

 

They try to make an argument that it saves money over a kettle as people tend to boil too much water. If you boil the kettle 10 times a day this would be true of a Quooker. This less well insulated device would probably need you to be boiling the kettle 13-14 times a day to save anything in terms of running costs. We certainly would never have boiled the kettle more than 10 times a day.

 

The reality is that no one should be buying these for running cost savings. You might save 10p a day in electricity, but only if you drink a lot of tea/coffee, but they cost the best part of £500-1500 to buy and install which more than offsets this. For most people they also actually cost a bit more to run than a kettle.

 

 

I paid £549 for mine (an Intu) as couldn't really see the sense in paying the astronomical prices for a quooker. Intu comes with a 7 year warranty a 60 day free trial, so I didn't think twice about buying it. Little did I know that when I bought it in late November we wouldn't be in the house within 60 days to live with it and test it. But all in all, subject to seeing my bills, I think we're happy with it. It doesn't spit, it seems to work, and I'm sure I'll get used to the very slight noise which i don't think comes on as often as I thought it did, but I will do some more experimenting/stalking of my machine. I've also emailed the supplier to ask for energy efficiency info, running kw etc. just out of interest. I was more asking out of environmental concerns than cost, as i suspected the difference between switching it on overnight or not would not amount to much.

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Actually an interesting thing to do is consider how often you use an item versus how much it costs.

 

iPhones are supposedly expensive at £1000, yet I use my iPhone a lot more than my similar priced Quooker and my car which cost 80x as much. The running cost of the average car is now around 50p per mile.

 

Clearly some things just have to be more expensive as they cost more to make, but there is not alway a lot of logic in people's spending decisions. Basically people spend money on things they like and don't particularly study the utility. How could you possibly explain people spending £10 a day on a packet of cigarettes!

 

Enjoy your tap. I am sure it does the job you wanted of it, which is all you can ask for.

 

 

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3 minutes ago, AliG said:

Enjoy your tap. I am sure it does the job you wanted of it, which is all you can ask for.

 

 

Cheers. I wonder whether just putting empty egg cartons around it will make it quieter.

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